On May 18, 1980, Mt. St. Helens, an 8,364 foot active volcano in Washington state, erupted. It was the most massive volcanic eruption in recorded history. The eruption destroyed 250 homes, 150 miles of highways and 47 bridges. 57 people were killed. The eruption was so powerful that it blew the top off of the volcano, reducing it over 1,200 feet in height. Over 230 square miles of land surrounding the volcano was completely flattened. The eruption was calculated to be as powerful as 27,000 atomic bombs.