Nepal-Tibet Flood Death Toll Climbs to at Least 469 as Rescuers Brace for Possible Second Surge

The death toll from Wednesday's flash flooding along the Himalayan border has risen to at least 469, with hundreds of people still missing on both sides of the Nepal-China frontier.

Nepal has reported the heaviest casualties. In Tibet, officials have confirmed three deaths and listed more than 550 people as missing. It was not immediately clear whether the two counts overlapped.

Rescuers searching the devastated area are "on edge" after warnings that a second flood could hit, a Red Cross official told the BBC. A lake of rising water has formed near the China-Nepal border, and officials fear it could burst its banks and send another surge through the valley.

The U.S. Geological Survey said the flooding was triggered by a "glacial collapse." Local officials told the BBC that a collapsed glacier sent a huge wall of water and debris through houses and roads, destroying a key border crossing used by travelers and local communities.

The disaster has forced a difficult rescue effort in steep, fragile terrain. Roads and bridges washed away in the surge are cutting off some villages, and aid workers are trying to reach survivors while also monitoring the growing lake higher up the valley.

The region is one of the most visited mountain corridors in the Himalayas, drawing tens of thousands of tourists and pilgrims each year. The BBC has been speaking to relatives of the missing; two sisters whose parents are unaccounted for said, "We just love them a lot and want them to come home."

The flood has also renewed attention on the dangers of glacial collapse in the high Himalaya. Scientists have warned that rising global temperatures are making high-altitude glacier landscapes more unstable, increasing the risk of sudden floods in valleys that are often densely used for tourism, trade and settlement.