Earthquakes are caused by movements in the earth's crust that generate shaking and vibrations. They can cause significant damage depending on their magnitude and intensity. While earthquakes occur frequently around the world, some areas are more prone to them than others. Major earthquakes since 1900 include a 9.5 magnitude quake in Chile in 1960 and a 9.0 magnitude quake off the coast of Indonesia in 2004 that triggered a devastating tsunami. Scientists have gained significant understanding of where earthquakes are likely to occur but still cannot reliably predict specific future events. Structures can be designed to better withstand shaking but no building can be completely earthquake-proof.