For months in early 1980, scientists, journalists, sightseers, and nearby residents listened anxiously to rumblings in Mount St. Helens, part of the chain of western volcanoes fueled by the 700-mile-long Cascadia fault. Still, no one was prepared when an immense eruption took the top off of the mountain and laid waste to hundreds of square miles of verdant forests in southwestern Washington State. The eruption was one of the largest in human history, deposited ash in eleven U.S. states and five Canadian provinces, and caused more than one billion dollars in damage. It killed fifty-seven people, some as far as thirteen miles away from the volcano's summit. Shedding new light on the cataclysm, author Steve Olson interweaves the history and science behind this event with page-turning accounts of what happened to those who lived and those who died.