It is the most common danger and can cause many other secondary effects which are listed below. Objects can fall from shelves, ceilings, building, etc. Fires are caused by disruption of electric, gas, or oil lines which can rupture from the ground shaking. Due to the ground shaking, avalanches cause snow to behave like a liquid and slide down a mountain. Avalanches can bury mountain side homes and destroy forests.
Land slides involve dry soil, and mud slides are caused by a water and soil mixture.
When the dam breaks the water escapes, flooding the surrounding area. When wet sand is subjected to repititious motions the pressure of the water between the sand grains increases untill the pore pressure is equal to that of the external pressure of the soil. It is now in a dense liquid state instead of a solid state. The flow of the soil liquefaction causes large buildings and other structures to tilt. The gradual drawdown movement of strata due to compression.