GENEVA

Authorities in Switzerland on Friday remained on high alert after a massive glacier collapse buried much of the village of Blatten in the Lotschental valley on Wednesday afternoon.

The collapse of the Birch Glacier unleashed an avalanche of mud, rocks, and ice, described by the Swiss Seismological Service (SED) as "one of the largest mass movements ever recorded." Seismic signals from the event were measurable hundreds of kilometers beyond Swiss borders.

Although Blatten had been evacuated as a precaution on May 19, search efforts continue for a 64-year-old man who remained in the area despite warnings and is still missing.

The local government in Canton Valais declared a "special situation" on Wednesday morning to be able to "react as quickly as possible." The Swiss army deployed over 50 personnel to support operations. More troops and heavy equipment are on standby, though direct intervention remains too dangerous due to unstable terrain.

The collapse created a natural dam in the Lonza River, forming a reservoir that experts say could give way at any time. "The risk of a tidal wave and erosion is still high," experts told Swiss broadcaster SRF. Aerial reconnaissance is ongoing to monitor the threat.

Downstream villages -- including Steg-Hohtenn and Gampel-Bratsch, home to over 2,000 people -- have been warned to prepare for rapid evacuation.

"We urge residents to pack essential items and be ready to leave immediately," local authorities announced.

The Ferden Dam, further downstream, has been emptied to act as a catchment basin in case of a flood. Officials are cautiously optimistic it can withstand the pressure. "Even with enormous influences, this wall will hold," said Christian Studer from the canton's Natural Hazards Department.

With further landslides still possible, authorities are focusing on risk assessment and limiting the number of people in vulnerable zones.

Early warnings credited with saving lives

Speaking on the incident, the World Meteorological Organization (WMO) spokesperson Clare Nullis told reporters in Geneva that early warnings and swift action by Swiss authorities likely prevented a greater tragedy.

"Luckily, there are no confirmed casualties or deaths at the moment, one person reported missing," Nullis said.

She emphasized that the outcome highlights the vital role of early warnings and coordinated emergency response by saying: "That shows the importance of early warnings and early action. The Swiss authorities did do everything. It was like a textbook example of what should be done."

"The landscape will never be the same again," she said. "But it is an example of how we can use forecasts and warnings to save people's lives."

She also warned that the threat is not yet over, underscoring the need for continued vigilance in the region.