Dam that broke after heavy rains had been identified as dangerous years before

Buildings are inundated after flash floods triggered by sudden heavy rainfall swamped Rangpo town in India (AP Photo/Prakash Adhikari)

A glacial lake that overflowed in India, breaking through a major dam and sending deadly, ice-cold floodwater through towns downstream, had been identified by officials, researchers and environmental activists as dangerous years before the disaster.

The flood killed at least 31 people, officials said on Friday, and forced thousands of people to flee their homes.