Earthquakes are caused by tectonic movements in the Earth's crust. The main cause is when tectonic plates slide one over the other. The tectonic plates are always slowly moving, but they get stuck at their edges due to friction. Earthquakes may lead to diseases, a great loss for lives including disturbances in the ecosystem. Damages to roads, bridges, and destabilization of buildings. Earthquakes can also proceed to volcanic eruptions.