The seismic waves that do the most severe damage are surface waves.
Surface waves, unlike other seismic waves that travel deep through the Earth, travel just beneath the surface, like waves in water.
The slowest seismic waves, surface waves are the last to strike a region after an earthquake. P-waves proceeds through the Earth's deep layers by compression first. They cause very little damage.
S-waves are the second type of wave. They begin deeper in the Earth and travel up and down. When stronger S-waves reach the surface, they cause some harm.
The surface waves are the last to arrive. Their gradual movement close beneath the surface poses the greatest threat to man-made structures and natural landforms.