On May 18th, 1980, the volcanic eruption of Mt St. Helens shook the Western Seaboard to its core. A beautiful, mountain cone toping out at an altitude of around 9,600 feet, was leveled out to remove the top 1,300 feet at the summit after the eruption. Although the volcano was relatively active in the early 20th century, and not to mention that there might have even been a major eruption in 1800, according to the Mt St. Helens Forest Learning Center, this mountain was seen as a tranquil recreation area for travelers and community members.
On March 20th, 1980, an earthquake with a magnitude of 4.2 was detected by the new system of seismographs at the University of Washington deep beneath Mt St. Helens. This earthquake created a round the clock watch that ended up saving many lives. The mountain was then rocked by 4.0 magnitude earthquakes as many as three times a day from March 25th to March 27th.
On March 27th, the U.S. Geological Survey issued an official Hazard watch for Mt St. Helens. Instruments began to measure "volcanic tremors" (pulses of magma) and by late April, the bulge of magma that was being monitored was growing at a rate of 5 feet per day.
Finally, on May 18th, 1980, a 5.2 magnitude earthquake rocked Mt St. Helens. Within 15 seconds, the entire north face of the mountain had collapsed, releasing the trapped gasses and magma, overflowing at high speeds. The area that was devistated by the direct blast ranged up to 230 square miles from Mt St. Helens. After the initial blast, a second explosion happened at the summit of the volcano, causing a mushroom cloud of ash and gases to soar more than 12 miles into the air. The ash drifted into 7 states (more than 2,200 square miles).
Because of the extensive damage done by the eruption of Mt St. Helens, it has been dubbed the most destructive eruption in U.S. history. It is recorded that 57 people were known to have died as a result of the eruption, along with more than 200 homes being destroyed. Around 15 miles of railways and over 185 miles of roads were demolished, as well. Air traffic control in the North Western United States was temporarily shut down as a cause of the ash debris. It is estimated by the International Trade Commission that total damages cost around $1.1 billion.