Scientists say a flash flood in Nepal on Wednesday was likely caused by a big piece of a glacier breaking off.

This piece blocked a river for a short time.

The water behind it may have then rushed down with great force.

The flood killed at least 353 people.

More than 1,300 people are still missing.

The U.S. Geological Survey reported a glacier collapse of magnitude 5.2.

They used seismic data and satellite images.

Jakob Steiner is a scientist at the University of Graz.

He said the lower part of a glacier fell off.

The falling ice may have felt like a bomb exploding.

Researchers say it is too early to link the disaster directly to global warming.

But they noted that rising temperatures make such events more likely.

This is especially true in the Himalayas.

These mountains are warming faster than many other places.

Water levels in affected rivers rose by up to 9 meters in 30 minutes.

The Hindu Kush Himalaya has the largest amount of snow and ice outside the polar regions.

About 78% of its glacier area is highly exposed to warming.

Scientists say melting glaciers can make glacial lakes bigger.

They can also weaken mountain slopes.

This raises the risk of sudden floods and other dangers.

Steiner said the area has a history of destructive mountain events.

These include floods and avalanches.

He warned that what happened is "the new normal."

He said the risks will grow.

Experts call for better early warning systems and faster information sharing.

But they say watching thousands of glaciers is very hard.

In some cases, people have only minutes to act.