A part of the Mont Blanc glacier in Italy could collapse at any moment, Italian authorities warned, after closing roads and ordering the evacuation of huts on the side of the glacier.

A staggering 250,000 cubic meters (8.8 million cubic feet) of ice could break away from the Planpincieux glacier on the Grandes Jorasses mountain in the Mont Blanc massif, experts at the Valle d’Aosta regional government and the Fondazione Montagna Sicura (Safe Mountain Foundation) reported in an analysis.

While it’s impossible to predict the exact timing of the collapse, observations in August and September showed that the glacier was shifting at a speed of 50 to 60 centimeters (20 to 24 centimeters) a day, experts said.

“These phenomena once again show that the mountain is going through a phase of strong change due to climatic factors, therefore it is particularly vulnerable,” Stefano Miserocchi, mayor of nearby Courmayeur, said in a statement. “In this case, it’s a temperate glacier particularly sensitive to high temperatures.”

Miserocchi ordered the closure of roads in the Val Ferret valley and the evacuation of mountain huts in the Rochefort area, as precautionary measures. He added that a glacier collapse would not threaten residential areas or tourist facilities.

With 11 peaks above 4,000 meters (13,123 feet) between Italy and France, Mont Blanc is Western Europe’s highest mountain range and is popular with hikers, climbers, and skiers.

Alpine glaciers are melting as a result of rising global temperatures. According to the latest registry of glaciers, their surface area decreased from 609 square kilometers (235 square miles) in 1989 to 368 square kilometers (142 square miles) now — a fall of 40%.

Earlier this month, dozens of people took part in a “funeral march” to mark the disappearance of the Pizol glacier in north-east Switzerland. The glacier, in the Glarus Alps, has shrunk to a tiny fraction of its original size. Scientists say it has lost at least 80% of its volume just since 2006, a trend accelerated by rising global temperatures.

In a speech on climate change to the United Nations General Assembly in New York Tuesday, Italian Prime Minister Giuseppe Conte referred to the Mont Blanc warning.

“It is now news that a glacier on Mont Blanc risks collapsing,” he said. “It’s an alarm that cannot leave us indifferent. It must shake us all and mobilize us.”