Some common failures in construction make buildings in hilly areas vulnerable to quakes.
l Random rubble stone masonry bearing walls. These collapse easily as there is no interlocking to hold them together.
l A large number of gable walls (the triangular part of a wall that supports sloped-roofs) collapse, partially due to their own mass but also due to the lateral thrust of roofs.
l Masonry walls fail due to faulty shape of stones/poor bonding/failure of corners due to lack of corner strengthening/failure of rear retaining walls/buckling failure of load bearing masonry due to lack of thorough stone/non-load bearing walls have failed by overturning.
l Collapse of roofs is largely due to failure of masonry walls and gable walls.