The correct answer is - seismic waves.
The earthquakes are a result of the interaction between the tectonic plates, Once there's a crack opened deep inside the ground, parts of the crust crumble, and when they do they release enormous energy. This energy in the ground creates very strong and fast vibrations, better known as seismic waves. The seismic waves can be devastating, depending on their strength of course, but a stronger earthquake will for sure result in lots of deaths and material damage, as we have witnessed numerous times over the years.