The slide was triggered by road cutting and mass loading at crown position follwed by saturation with water and building of pore pressure. 

An interim report on Preliminary slope stability assessment of recent disaster affected areas of Pithoragarh District, Uttarakhand by A Bishwapriya, Suptg. Geologist, M V Dhakate and P K Gajbaiye, Sr Geologist, M IV, NR,Dehradun (LHZ/NR/UPUK/2013/056)
UK/Pith/ Seraghat- Thal/SZ/0003
State Highway
Training of water flow by providing hume pipe or aqueduct below the road and construction of road over it. Proper drainage arrangements by keeping the subsidence area free from surface water. Repairing of the retaining walls.
Combined effect of the multiple factors like saturation of loose mass and development of pore water pressure by subsurface water led to reduction of shear strength of mass. Also other factors were loading at crown portion and road cutting.