Blatten Glacier Disaster (May 2025)

The Blatten Glacier Disaster is a major natural disaster that occurred on 28 May 2025 in the village of Blatten, located in the Lötschental valley of the Swiss canton of Valais. A massive landslide of earth mud and rock, triggered by the collapse of a large section of the Birch Glacier, destroyed approximately 90% of the village. Despite preventive evacuations carried out prior to the disaster, one person went missing.

Blatten is a mountain settlement in the Lötschental valley of the canton of Valais with a population of approximately 300 people. On 19 May 2025, due to a series of small rockfalls and increased seismic activity in the region, authorities carried out a preventive evacuation of nearly the entire village.

The Swiss Seismological Service (SED) recorded the first seismic movements on the morning of 19 May and observed that the mountain slope in the area had become unstable. During this period, warnings increased regarding the potential for rock and ice masses from above the Birch Glacier to slide downward.

On 28 May 2025 at approximately 15:24 local time, a large section of the Birch Glacier broke off and collapsed onto the village of Blatten. The collapse generated a seismic shock measuring 3.1 in magnitude, which was felt not only locally but also in various parts of Switzerland.

Drone footage released by SRF (Swiss National Broadcasting Corporation) showed that a significant portion of the village was buried under layers of mud rock and ice. The riverbed of the stream flowing through Blatten and surrounding forested areas were completely covered.

Authorities reported that most homes in Blatten had been destroyed while the remaining structures suffered severe damage or were buried under debris. Approximately 90% of the village area was completely obliterated. The village’s infrastructure including roads and natural resources became unusable due to the disaster. One person a 64-year-old man went missing during the collapse. Drone and thermal cameras were used in search and rescue operations.

Following the disaster some sections of the Lonza River bed were filled with collapsed debris leading to the formation of a new lake due to water accumulation. Due to the risk of overflow or erosion of surrounding soil the authorities evacuated certain buildings in nearby villages such as Wiler and Kippel as a precautionary measure along the river course.

Valais Cantonal Director of Security Stéphane Ganzer stated after the event: “A major disaster has occurred in Blatten; 90% of the village has been destroyed.” Swiss Confederation President Karin Keller-Sutter also posted on the social media platform X saying “Losing your home is a terrible situation. I am deeply sorry for the people of Blatten.” The president further emphasized that the area remains dangerous and urged the public not to approach it.

The Blatten Glacier Disaster was a large-scale natural catastrophe that occurred on 28 May 2025 in the Alpine village of Blatten, situated in the Lötschental valley of Switzerland’s Valais canton. Triggered by the collapse of a massive section of the Birch Glacier, the event unleashed a destructive flow of soil, mud, and rock that buried approximately 90% of the village. Despite prior evacuation measures, one individual was reported missing following the disaster.

Blatten is a mountain village located in the Lötschental valley, with an estimated population of 300. On 19 May 2025, following a series of minor rockfalls and noticeable seismic activity in the area, Swiss authorities initiated a precautionary evacuation of nearly the entire village.

According to the Swiss Seismological Service (SED), the first tremors were recorded on the morning of 19 May. These initial movements, coupled with increasing instability along the mountainside, prompted warnings about the potential descent of rock and ice masses from the upper flanks of the Birch Glacier.

At approximately 3:24 p.m. local time on 28 May 2025, a substantial portion of the Birch Glacier broke off and collapsed into the valley, engulfing Blatten in a powerful landslide. The event generated a tremor measuring 3.1 in magnitude, which was felt not only in the immediate region but also across other parts of Switzerland.

Drone footage released by the Swiss national broadcaster SRF revealed that a significant portion of the village was inundated by mud, rock, and glacial debris. The footage further showed that the river traversing Blatten, as well as the surrounding forested valley slopes, were entirely submerged beneath the landslide material.

Authorities confirmed that the majority of homes in the village of Blatten were either destroyed or severely damaged, with many structures buried beneath layers of mud. An estimated 90% of the village area was rendered uninhabitable. Critical infrastructure—including roads, public utilities, and local natural resources—was rendered inoperative as a result of the disaster. One individual, identified as a 64-year-old male, went missing during the collapse. Search and rescue operations deployed drones equipped with thermal imaging technology to locate the missing person.

In the aftermath of the collapse, sections of the Lonza River’s course became obstructed by debris, resulting in the formation of a new lake. Due to concerns over potential flooding or soil erosion, precautionary evacuations were also carried out in downstream municipalities such as Wiler and Kippel.

Stephane Ganzer, Head of Security for the canton of Valais, stated in a press briefing: “A major catastrophe has occurred in Blatten; approximately 90% of the village has been destroyed.” Swiss Confederation President Karin Keller-Sutter also addressed the nation via the social media platform X, stating, “It’s terrible to lose your home. I am deeply saddened for the residents of Blatten.” She emphasized the ongoing risk in the area and issued a public advisory urging citizens to refrain from approaching the affected zone.