The avalanche and flooding in the Dhauli Ganga, Rishi Ganga and Alaknanda rivers that swept away homes and left at least 70 people dead and 125 missing, was caused by a massive rockslide, said scientific findings released on Friday by International Centre for Integrated Mountain Development (ICIMOD), an intergovernmental body.

According to a report in Times of India, the rockslide, right below the Ronti peak, and the energy of the fall melted the ice creating the source of flood.

The ICIMOD findings said the energy of the fall of about “22 million cubic metres of rock mixed with ice and snow” remobilised the debris and ice on the valley floor deposited by previous events, “pushed the stream water and created an excessive flood wave”.

Meanwhile, an alternative Bailey bridge was built over Rishiganga to restore connectivity to 13 villages of Uttarakhand’s Chamoli district which had been cut off after a bridge was washed out in the floods on February 7.

The construction of the bridge began on February 25 and it was scheduled to be completed by March 20 but the Border Roads Organisation (BRO) worked overtime to complete it well before schedule, said chief engineer of BRO’s Shivalik project AS Rathore.

The newly built Bailey bridge opened for the public after trials on Friday.