Mount Saint Helens

Mount St. Helens, Washington, erupted on May 1980. When Mount St. Helens erupted, the top 1300 ft disappeared within minutes. The blast covered an area of more than 150 square miles and sent thousands of stone and ash into the upper atmosphere. It tore off the mountain's top and blasted a giant crater in its side.

The eruption blew down giant trees like they were match sticks. Almost all of the animals that lived in the forest were killed as well. Birds were particulary hard hit. Some birds survived the eruption but died later because the insects and plants they ate had died.

After the eruption, streams were choked with rock and mud. When water mixed with rock and mud, it created volcanic mudflows that were able to move down the volcano's slopes. On the steepest slopes, themudflows traveled up to 144 kilometers per hour (90 miles per hour). Some of the mud flows were as high as a six storie building!