After a natural disaster, we often measure its impact with numbers: buildings destroyed, repair costs in millions, lives lost. But these figures hide the real story. They make the devastation seem orderly, almost predictable. The truth is, disasters are chaotic. Their sheer force amplifies every choice—whether to stay or go, run or hide. Things could have unfolded differently. How would we describe them then?
On the northern shore of Lake Maggiore in Locarno, Switzerland, the Maggia River begins its journey. Flowing northwest, it twists past sandy, shaded beaches, through rocky gorges, and into a wide glacial valley where waterfalls cascade down forested slopes for much of the year. About 20 kilometers upstream, at the base of Pizzo di Brünesc mountain, the river splits. This is the upper Maggia Valley. To the west lies Val Bavona, with its historic stone-roofed villages. To the east, equally steep and lush, is Val Lavizzara. And high in Val Lavizzara, at 1,000 meters above sea level, sits Campo Draione.
Campo Draione might just be the most beautiful football pitch on Earth—or at least in Switzerland. Perched on a narrow ledge above a mountain stream, hidden from the road by trees and encircled by pine-covered peaks, it was built in the 1950s on rubble from nearby hydroelectric projects. Since 1970, it has hosted one of the valley’s most beloved events: an annual two-day, eight-a-side football tournament with 18 teams from across Ticino.
Most years, the tournament falls on the first weekend of July, but in 2024, it was moved earlier to avoid overlapping with a fireworks display in Locarno. So on June 29, a warm Saturday morning, hundreds gathered at Campo Draione. The mood was festive—those not playing ate ice cream, bought drinks from a marquee, or swam in the stream at Piano di Peccia, a village just a 10-minute walk away across a narrow bridge spanning a deep green ravine.
The highlight would come that evening: an open-air party under the stars, with a stage, lights, three bands, and a DJ, lasting until dawn. Revelers would then retreat to tents pitched along the field or in nearby farmland.
But that morning, Daniele Rotanzi, the lead organizer, kept checking his phone. MeteoSwiss, the national weather service, had issued a level 3 storm warning—a “significant hazard”—for the region. “Rain was certain,” recalls Rotanzi, a fit man who looks younger than his 40 years. After consulting the 10-person volunteer organizing committee, they decided to move the stage inside the marquee—a wooden platform just 50 cm high. Less impressive, but safer, they agreed.
The SwissMeteo office for the southern Alps sits on a steep hillside north of Locarno. From its forecast room, the Maggia delta unfolds below—a vast fan of land stretching 2.5 kilometers into the lake. Few European rivers react as quickly to rain as the Maggia, swelling rapidly. Just months earlier, in September 2023, its waters had surged 17 times their normal volume in hours—a deluge the landscape absorbed without much fuss.
But by lunchtime that Saturday, the meteorologists were uneasy. A week earlier, a thunderstorm had triggered a debris flow that destroyed the hamlet of Sorte in Graubünden, killing two people with one still missing. Sorte was now uninhabitable. Now, they watched as low pressure moved from France toward southern Germany, colliding with hot air pushing north from Italy. In spring 2024, the Mediterranean’s surface temperature had been six degrees above its 30-year average, and in recent days…The heat had broken June records. When these hot, humid air currents met the towering curve of the Alps, they either veered away or clashed and rose, setting the stage for another powerful storm.
At 1:30 PM, meteorologists held a video call with police, firefighters, emergency services, transportation officials, and regional experts in hydrology and geology. For the first time in Ticino, they escalated the thunderstorm warning to its highest level—a “severe” hazard (Level 4), with risks of flash floods, destructive winds, landslides, large hail, and lightning. Radar showed heavy rain in the upper alpine valleys of Ticino and violent storms moving through central and southern areas like Locarno, Bellinzona, and Lugano.
Warnings went out on local TV, radio, social media, and the popular MeteoSwiss app. Police and fire departments alerted local command centers, while river authorities, forestry teams, and landslide-prone towns were notified. But the forecasts were frustratingly vague—no one knew exactly where the worst rain would hit. MeteoSwiss’s internal model predicted extreme rainfall over the upper Maggia Valley, yet neither official briefings nor public warnings singled out that specific flash flood risk. Instead, the alerts covered all of Ticino.
Thunderstorms are among the hardest weather events to predict. Even if MeteoSwiss’s model pinpoints a storm’s center within 30 kilometers just once in ten attempts, the team considers it a success—assuming the storm even materializes. Most warnings are issued with a 70% certainty, but for thunderstorms, that drops to just 40%. As late as Saturday afternoon, the most likely scenario was no storm at all anywhere in the canton.
Daniele Rotanzi, from Piano di Peccia near Campo Draione, was among the crowd. About half the people there were also from the Maggia Valley, including his childhood friend Loris Foresti. The two had grown up together, swimming in local pools in summer and playing hockey on Prato-Sornico’s ice rink in winter.
Foresti, a meteorologist developing thunderstorm-tracking software for MeteoSwiss, was Rotanzi’s go-to for weather advice. When Rotanzi saw the Level 4 alert, he asked his friend what to expect. “It was Level 4,” Foresti said, “but you never know where it’ll hit. I thought—maybe we can still do the concert outside after it passes?”
The sky had a strange yellow tint from Saharan dust high in the atmosphere, and the air felt thick and humid. Light showers came and went through the afternoon, but the games continued. By 6 PM, as the last match ended, everyone hurried into the marquee. Switzerland was about to face Italy in the Euro knockout stage, and the match was projected onto a white sheet while grilled ribs were served at long tables. Between 300 and 400 people packed inside, their cheers drowning out the rain drumming on the tent roof.
By 8 PM, Switzerland had pulled off a historic 2-0 victory, and though the rain was heavy, the celebrations went on. The crowd rushed to the bar, and at 9 PM, the first band—a parody “farm metal” group—started playing. Outside, the thunderstorm had begun.
Much about thunderstorms remains a mystery.The greatest challenge lies in predicting when and how these events will happen—a problem connected to one of physics’ biggest mysteries: turbulence.
Light a candle and blow it out. At first, the smoke rises smoothly, then it begins to twist and swirl. That chaotic motion is turbulence, and despite our understanding of the universe, we still can’t predict exactly how it will behave. Unlike distant phenomena like black holes, turbulence is something we experience daily—in flickering flames, the spread of a scent through a room, or the crashing of waves. When smooth, orderly flow breaks into turbulence, large whirls split into smaller ones, each influencing the others, growing exponentially more complex with every passing second.
Turbulence shapes all weather systems—it’s why meteorologists can’t forecast beyond two weeks—but thunderstorms are especially driven by these chaotic currents. As the planet warms, the most violent storms may grow even fiercer, yet they remain stubbornly unpredictable.
By midnight on Campo Draione, heavy rain had been falling for nearly three hours. Inside a marquee, a folk band played on a makeshift stage. Foresti stood with his back to them, watching the downpour outside, the mountains illuminated by relentless lightning flashing several times a second.
“I love thunderstorms,” Foresti said. “They excite me. I took pictures.” As a meteorologist, he knew this wasn’t just one storm but a series fueled by a stalled weather front, sucking in warm, moist air “like a thunderstorm machine.”
Then, unease crept in. The front should have moved by now. “It has to stop,” Foresti remembered thinking. But the rain kept falling. His thoughts turned to the valley below, to his parents’ riverside tavern and the people there. He and the hundreds around him were in grave danger. As the band played on, Foresti began trembling with fear.
Normally, storms come in waves with breaks in between. But that night, they struck one after another, relentless, concentrated along a narrow stretch of land—roughly 20 kilometers long and nine wide—following the jagged ridge 2,500 meters high between the Maggia valleys. Outside this zone, rainfall dropped sharply; nearby Locarno saw almost none. But on the ridge, over 50 millimeters of rain fell per hour—50 liters per square meter—and it landed on snow.
Ticino’s climate is usually warm, almost Mediterranean, and by late May, any snow would typically be gone. But in 2024, heavy April snowfall lingered on the peaks even a month into summer. The melting snow saturated the ridge, and the rain rushed over already soaked ground. By the time it reached the treeline, still 1,000 meters above the valley villages, the flood—thick with debris—had enough force to move boulders and snap trees.
“A debris flow is impossible to simulate,” said Andrea Salvetti, the canton hydrologist. “The water moves, but so does everything it carries—a single rock can change its path, a pile of debris can block it. You can’t predict where it will go.”
At 12:15 a.m., a woman burst into the marquee. She had just driven up to fetch her daughter and was frantic. “She said it was insane,” Foresti recalled. “Stones were bouncing onto the bridge, others were moving beneath it.”
“Not everyone believed her,” Foresti remembered. “Some kids said she was talking nonsense, and she got angry.” But Foresti recognized her description—a debris flow, where “stones float on mud and…”Here’s the rewritten version in fluent, natural English:
The situation with the water was worsening. He recognized the need to prevent panic. “I tried to stay calm, but I wasn’t calm at all,” he admitted.
As the third band of the night prepared to start their set, Rotanzi checked in with the DJ who was scheduled to close the party. At 12:20 AM, Rotanzi texted, “What time will you arrive?” The DJ replied a minute later: “Hey, I’ll be there in 10 minutes! The roads are terrible—it’s taking longer than expected.” Rotanzi responded with a thumbs-up emoji. Then the power went out completely.
People turned on their phone flashlights as rain pounded loudly on the roof. About 200 people stood in the dark. Someone mentioned there was a generator in a nearby village, and a group went to retrieve it. Then Rotanzi’s phone buzzed—it was the DJ again. “The river’s overflowing,” he wrote. “I can’t get through.” He sent a photo showing water flooding across a road in his headlights. Rotanzi recognized the location—there wasn’t normally a river there. “Turn back,” he replied, then immediately called the police.
The police said units were on their way. Rotanzi then called the fire chief, who instructed, “Keep everyone inside the tent.” There had already been flooding and landslides nearby. The group searching for the generator had to turn back when they encountered water flowing over a bridge just 50 meters away.
Inside the marquee, Rotanzi climbed onto a table to address the crowd. The road was blocked—no one could leave. Everyone needed to stay put. “You could tell people understood something serious was happening,” Rotanzi recalled. “Everyone listened quietly.”
Meanwhile, the heavy rain continued unabated for four hours along the mountain ridge. That night, the storm dumped 30 billion liters of water—weighing 30 million tons in its pure form, and even more when mixed with debris. The deluge uprooted trees, eroded the ground beneath rocks, and sent boulders tumbling down the mountainside.
At about 1,300 meters elevation, the rushing water and debris suddenly stopped, blocked by a massive boulder that created a natural dam in a steep channel. Normally, this channel never exceeded three meters deep, but now the backed-up water rose over 30 meters high.
The historic village of Fontana—located on the opposite side of the ridge from Campo Draione—was built on green terraces with ancient stone buildings covered in moss. When the makeshift dam burst, Fontana was struck by a devastating wave of water, debris, and 300,000 cubic meters of rock. The force demolished walls and crushed cars like paper. Most astonishingly, the 2,000-ton boulder that had caused the blockage remained upright as it rode the floodwaters, traveling 450 meters through the village—taller than the houses it passed—before coming to rest. The village was split in half, buried under rubble 500 meters long, 500 meters wide, and up to 13 meters deep.
Tragically, five people died. Three German tourists who had left their house when the dam burst were caught outside and killed—their home survived untouched. At the village’s lower end, a local couple who had apparently sheltered inside their home perished when the building was completely destroyed.
Back at Campo Draione, the atmosphere had settled somewhat. The unheated tent grew cold, and people huddled together for warmth under tarps, foil blankets, and plastic tablecloths. A single battery-powered lamp hung from the ceiling. Through the dim light, Rotanzi noticed the stage technician approaching nervously—he had something urgent to show.
Stepping out into the rain, Rotanzi saw that the forest just five meters from the marquee had disappeared. The edge of the outdoor stage now extended over nothingness, with a parked van’s wheels dangling over the void. Thirty meters below, he heard the river roaring. In the flashing lightning, he could see the exposed rubble foundation of the field—it looked like mere gravel beneath his feet.Rotanzi stood in shock. Just five meters from the edge of the marquee, where the forest had once been, there was now nothing but emptiness. The bridge to the village was blocked. Uphill, through thick, rocky woods, stood a house only 50 meters away—but even if they reached it, there was no way 200 people could fit inside. Was anywhere safe? The slope above the festival grounds was steep and towering. Who knew what might come crashing down? Inside the tent behind him, partygoers shivered in their soaked summer clothes, oblivious to the disaster. Rotanzi knew he had to decide: tell them the truth and risk panic, or stay silent and risk the entire tent—and hundreds of lives—being swept away.
By day, Rotanzi worked as an insurance actuary, calculating risks in much calmer settings. Nothing had prepared him for this. He hurried back into the marquee, found two friends from the organizing committee, and led them outside to see. “Nothing was certain that night,” Rotanzi later said. “But my biggest fear was panic breaking out.” Half the crowd weren’t locals, and many had been drinking. If they fled the tent, hypothermia would set in quickly. After explaining his reasoning, his friends agreed. They stationed a security guard at the tent’s edge—if he spotted any new movement, they’d evacuate. Until then, the landslide would remain a secret.
Inside, Foresti sensed something was wrong. He could hear the river—odd, since the forest usually muffled the sound. He’d seen Rotanzi and the others leave together. After a moment, he followed.
“The forest at the end of the tent was just… gone,” Foresti said. He shone his phone’s flashlight into the darkness, but the rain swallowed the beam. He tried taking a photo, but the screen showed only black. “Then, in a flash of lightning, I saw the river for just a second. Floodwater is usually chaotic—like a washing machine—but this was higher, smoother. My mind couldn’t process it. It wasn’t a river I recognized.”
He found Rotanzi, who urged him to stay quiet. Foresti understood, but shouldn’t they at least move people away from the tent’s edge? The rain had been pouring for nearly six hours. The whole structure could collapse. Rotanzi tried subtly convincing those near the back to shift away, but without explaining why, his efforts fell flat. Some refused to move.
Meanwhile, Giorgia Mattei sat inside the marquee. Across the destroyed bridge, in Piano di Peccia, her mother, younger sister, and sister’s children were trapped in their family home. A photo in their WhatsApp group showed water lapping at the front door. Her sister messaged that she was terrified—rocks and trees were tumbling down the mountain. She and their mother had retreated upstairs; the children still slept. Their mother wrote that the henhouse had been washed away.
At 2:30 a.m., Giorgia sent a message assuring everyone they were safe at Campo Draione. Her sister replied that cars were slamming against the house. Their mother vowed they’d stay together. Giorgia begged them to keep to the higher floors.
On the other side of the Alps, in the Jura, Giorgia’s father woke to the flurry of messages. He typed that he couldn’t reach them by phone—but no one saw it. By then, all their phones had gone dead.The Visletto Bridge over the Maggia River had collapsed, splitting in half. This 80-meter stone bridge was the only transportation link to the upper valleys and carried vital water pipes and power cables. When it gave way, the upper Maggia valleys were completely isolated—cut off from phone service, internet, running water, and electricity.
The rain had finally stopped, but there was nothing to do except wait for daylight.
At dawn, red-and-white rescue helicopters swarmed into the valleys. By 5 a.m., just two hours after the bridge collapsed, Canton Police Chief Commander Matteo Cocchi had declared a state of emergency. Under Captain Antonio Ciocco’s leadership, police took over Locarno’s disaster coordination bunker and repurposed a school in Aurigeno, using its football field as a makeshift helicopter landing zone. Ciocco called for immediate support from fire departments, forestry services, mountain rescue teams, and the military.
As the helicopters relayed the first aerial images of the devastation, the full scale of the disaster became clear. Over 50 debris flows had torn through the landscape, reopening old riverbeds and obliterating roads. The village of Fontana was nearly unrecognizable—its lush terraces now buried under a sea of gray rock.
“The first question was, ‘What’s beneath all that stone?'” Ciocco said. “Are there injured people? If you can see them, you know they need help. But what you can’t see… you can only imagine.”
On the command center’s screens, images of Campo Draione appeared. Where the village bridge once stood, a massive landslide—100 meters wide and four times as long—stretched from the forest to the river, carrying an estimated 250,000 tons of rock. The riverbank had been swallowed by a 20-meter-wide chasm. Miraculously, the festival marquee still stood.
Back at the festival grounds, partygoers emerged into chaos. Crowds gathered at the edge of the landslide, staring in shock at patches of grass dangling over nothingness. Through a gap in the trees, they could see Piano di Peccia half-buried in rubble, while the river—now three times its normal width—raged through the shattered village.
When phones stopped working, someone retrieved an emergency two-way radio from their car. Using its satellite function, they contacted mountain rescue, who instructed them to stay put. Huddled in cars for warmth, they tuned into the radio. FM signals were dead, but DAB still worked.
“At 6 a.m., we heard someone say there were 200 people in Campo Draione, and all were safe,” Rotanzi recalled. “That was a huge relief.”
Soon after, a helicopter landed. Rescue teams assessed the situation but left quickly—40 children stranded at a summer camp in Mogno took priority. The catering crew served breakfast.
“We weren’t sure if we’d be evacuated that day,” Rotanzi said. “So from 6 a.m., we updated everyone every two hours.” They had food, shelter, and camping gear, but no way to contact loved ones. Unbeknownst to them, frantic parents had flooded police phone lines—500 calls got through, but 6,000 failed. It wasn’t until 10 a.m. that authorities set up a dedicated emergency number.
Giorgia Mattei shivered in the cold. Wrapped in aluminum foil and wearing oversized army boots, she huddled in a friend’s camper van. Her mother, sister, and nieces were just a few hundred meters away—but she had no idea if they were alive.
Around 8 a.m., she heard a farmer was trying to build a makeshift bridge. He had flagged down a helicopter with a laser pointer and crossed the landslide to check on his cows. Giorgia joined him, helping chop down a tree to span the torrent.
Struggling in the borrowed boots, she stepped onto the shaky trunk. “My legs were shaking,” she said. “I was terrified of falling.”
A debris flow—The floodwaters from the forest had struck the family home. Giorgia spotted the henhouse, now 50 meters away from its usual place—miraculously, the chickens had survived. Rubble blocked the front door of the house, and the ground floor was covered in mud. But her mother, younger sister, and the children were unharmed.
They had no way to reach her father. He had driven five hours through the night, convinced his wife, children, and grandchildren had all perished. He had tried, unsuccessfully, to hitch a ride on a helicopter. He argued with police who attempted to stop him, then hitched rides and climbed through debris, pushing deeper into the disaster zone as others fled. At 5:30 p.m., he finally reached his ruined home—and found his family safe.
On Campo Draione, the army had arrived. Evacuees boarded a Super Puma helicopter in groups of 15, leaving behind tents, instruments, and cars. “It’s an image I’ll never forget,” Rotanzi said. “A football pitch is supposed to be a place of joy, and seeing this massive military helicopter there was such a stark contrast… It was both incredible and horrifying at the same time.”
Rotanzi was on the second-to-last helicopter—an eight-minute flight to the school in Aurigeno. From the window, he stared down at the devastated landscape, stunned by the destruction. “All night, I kept thinking, Damn—these people are here because of us,” he admitted. Relief washed over him—until his phone buzzed. Hundreds of messages. Missed calls. “That’s when it hit me,” he said. “We were returning to reality.” As the helicopter landed, he broke down in tears.
No one knows exactly how many people were in the upper Maggia valley that night. The registered population of 1,000 swells in summer, and by Sunday evening, over 500 were reported missing. It took three days to account for nearly everyone. “At first, there were hundreds,” said Captain Ciocco. “Then 50, then 10. Until finally, just one person remained unaccounted for.”
The missing man had been at Campo Draione. A 22-year-old local, he might have left the party before midnight to rest in his car, parked near the bridge. Seven people were confirmed dead in the disaster—five in Fontana and two in Prato-Sornico. Despite a massive search involving over 2,200 people, neither the man nor his car was ever found.
Foresti wrestled with doubt: “Did I underreact? A few weeks later, there was another Level 4 warning—just some hail, nothing more.” Given the same information again, he admitted he wouldn’t have acted differently.
Rotanzi faced criticism, both publicly and privately, for not canceling the event. “The warning was for that night,” he defended. “If we’d canceled at 6 p.m., people would have gone to their tents—right where the floods and rocks later hit. It could’ve been even worse.”
Should the police have stepped in? “We can’t order an evacuation without more precise data from MeteoSwiss,” Commander Cocchi explained. But MeteoSwiss can’t provide that level of detail—without a scientific breakthrough in predicting turbulent flows, they may never be able to. Despite their resources and vigilance, Swiss authorities faced a chilling realization: this could happen again.
The mountains have their own logic—trees growing toward the light, water carving paths over millennia. Now, much of that order has been overturned. For months, machines labored to clear paths through a wasteland of fallen rock, struggling to undo what a few hours of rain had wrought. Lichen will take years to return, then moss, then soil. People who’ve lived here their whole lives—whose grandparents raised them here, who knew these slopes as children—are now learning the landscape anew.The Grammar of a Shattered Landscape
“I used to fish behind my parents’ tavern,” says Foresti. “I knew every pool of water. It was all forest back then, and the river took a completely different path. Now it’s filled with stones. Trails have disappeared. Where there was once forest and grazing cows, now I see a mountain. The forest is gone.”
The flash flood in June 2024 was one of the most violent the region had seen in 200 years. Few believe it will be long before the next one strikes. “Heavy rain events like this seem to be happening more often,” says Luca Nisi, deputy head of Locarno’s SwissMeteo team.
But flooding isn’t the only threat. Almost a year after the storm in the Maggia valley, the Swiss village of Blatten was destroyed—buried by rocks that fell onto a glacier, causing it to collapse. The event was likely triggered by melting permafrost. Over the past decade, Switzerland’s average temperatures have been 2.9°C higher than preindustrial levels. These dangers aren’t confined to the Alps—just last week, hundreds were evacuated in Italy’s Dolomites due to rockfalls caused by thawing permafrost.
As Switzerland debates the future of its mountain communities, retreating from the land might seem like the simplest solution. But the climate crisis is complex. Near Campo Draione, a mudslide emerged from the forest where no natural drainage channel existed. At its source stood a cluster of dead trees, killed by bark beetles thriving in recent hotter, drier summers. Without their roots to hold the soil, the ground gave way.
Who will track these changes? Mountain residents may be caught off guard, but they possess an intimate, irreplaceable knowledge of their land and its subtle shifts. Rather than abandoning these landscapes, perhaps it’s time to engage with them more deeply than ever.
The football tournament went ahead in 2025. Grotto Pozzasc, the bar owned by Foresti’s parents, remains open. The communities are recovering, but they carry scars.
“I don’t feel safe during thunderstorms anymore,” says Giorgia. “The thunder frightens me.” That fear may feel new, but it’s not unnatural. It’s how humans once experienced the weather—not as a forecast on an app, predictable and contained, but as an uncontrollable force. For a brief moment in history, we thought we had tamed the weather. All along, we were only making it wilder.
(This is an edited version of an article first published in Das Magazin.)
