“It has probably been the worst 24 hours of my life,” Dr. Radhika Sharma, the daughter of one missing American couple, said.

Nearly 400 tourists have been swept away and entire villages are feared lost after an avalanche triggered massive flash flooding in the Himalayas.

The recent flash floods in Nepal and surrounding border areas have left hundreds missing. The relentless torrential rains have resulted in devastating landslides, destroying…