Successful Institutional Risk Management (mostly)

Over the next couple of months, earthquake and ash eruption activity intensified at the mountain. A bulge in the north side of the mountain began growing at a rate of several feet outward per day. The US Geological Survey produced updated hazard analyses for the mountain that led the governor of the state of Washington, Dixy Lee Ray, to establish a sizeable evacuation area around the north side of the mountain, including a beautiful resort area, Spirit Lake, and widespread logging operations. Dixy was an anomaly in American politics, a scientist, faculty member in Zoology at the University of Washington, a former head of the US Nuclear Regulatory Commission, a woman who spoke her mind and stood her ground. For the next couple of weeks the mountain dithered, the bulge grew, and pressure increased to lift the evacuation so people could get on with their lives. Dixy stood her ground, mostly.

The Role of Luck

On Sunday, 18 May 1980, at 8:32 AM, the bulge on the north side of Mt. St. Helens failed, becoming one of the largest recorded landslides. The bulge failure released the pressure on the magma vent, producing a side-blast of ash and pyroclastic flows, which eventually morphed into a nine-hour ash eruption that blanketed much of central and eastern Washington state, turning day into night as far as 300 miles away from the mountain. Approximately 60 people died, mostly in areas adjacent to, but outside, the evacuation area. There were about the same number of tales of harrowing escapes, hours of walking or driving through blinding, suffocating ash.

Elk Pass was right at the northeastern edge of the blow-down, the area where the force of the side-blast had blown down standing timber. Two or three dozen people died in the next few miles away from the mountain.

Governor Ray had bent to the public pressure and allowed a convoy of Spirit Lake residents to visit their homes on the day before the eruption to recover personal belongings. A similar convoy was forming up when the mountain blew.

I was hiking with our hiking club in the Columbia Gorge the morning of the eruption. We could see the ash plume from the Gorge; about three or four hours later we drove to a mountain-top on the south side of the river and watched the eruption for about an hour. Words fail me in an attempt to express the awe felt at watching the eruption. The engineer intones: sonically-choked turbulent flow, little cauliflowers of ash poking out of the plume and growing to a quarter- to a half-mile in diameter in a few seconds. The engineer didn't know about the deaths on the other side of the mountain, the closure of the interstate highway I-90 150 miles from the mountain, or "midnight" in Yakima, Ritzville, and Spokane.

My personal risk analysis and that of my geologist companion were thoughtful, and at least partially informed, but, ultimately, wrong. We were both lucky.

Governor Ray took the best advice she had and mostly stood behind it, but events proved the evacuation area to be too small. It is instructive to remember the public pressure to cancel the evacuation. By standing her ground, Dixy probably saved several dozen lives, maybe more.