Landslide appears to be triggered by the cutting of slope at steeper angle during road widening operation and left unsupported. Due to heavy rainfall in the area  shattered and slumped rock mass and debris mass/ slope wash material started to slide down.
An Interim Report on Preliminary  Geological  Slope Stability Assessment of the Recent Disaster Affected Areas in Parts of Chamoli District, Uttarakhand by Bhupendra Singh, Bhupender Singh, Ajay Kumar and Arindam Roy, Senior Geologists, M-IV, NR GSI Dehr
UK_CHA_MDR_ 062
Breast wall with weep holes and lined toe drain, improvement of drainage, sealing of cracks, retaining wall.
Slope cutting at steep angle made it unstable which was further aided by heavy rainfall. Saturation of slope material caused loss of shear strength of slope material.