Thousands of south Sound students participate in Mount Rainier eruption drill

PUYALLUP, Wash. — Thousands of lives are potentially at risk if Mount Rainier were to erupt and on Thursday, students in Pierce County practiced how they would escape if lahars began pushing through their communities.

This was the fourth year the lahar exercise has been conducted, and it has involved the Puyallup, Sumner-Bonney Lake, Orting, White River and Carbonado school districts, as well as partner agencies such as several of the surrounding police and fire agencies.

“A drill of this magnitude helps us practice our effectiveness in working together,” said Sarah Gillispie, the spokesperson for the Puyallup School District. “We realize we can't be 110% prepared for emergencies, but when we drill, we can evaluate the effectiveness and see where we can improve."

During the exercise, emergency operations centers at Puyallup, Bonney Lake, and Buckley were activated to oversee the safe relocation of students and staff from more than 50 facilities. About 8,000 students and staff participated in the evacuations on Thursday, while students at campuses on higher ground practiced sheltering in place.

Mt. Rainier is an active volcano with a high probability of erupting, according to the drill’s organizers. An eruption could send a lahar, or flow of mud and debris, through wide swaths of development. The communities on the volcano's northern and western sides are especially at risk.

“It would be like a flash flood, but think of a flash flood full of concrete and rocks and trees,” said Holly Weiss-Racine, a geologist and outreach coordinator with the United States Geological Survey (USGS). “Lahars are extremely destructive. They can pick up and move rocks that are the size of buildings."

The USGS predicts that a lahar event from Mt. Rainier could occur in the next 500 to 1,000 years, and if an eruption and lahar were to occur, it would put the lives of thousands at risk in Pierce County. Models run by the USGS predict that a lahar would reach Orting in about an hour, and then the flow would continue into Sumner before turning west toward Puyallup and eventually even Tacoma.

According to the school district's website, experts predict the valley floor in Sumner will fill to a depth of 30 feet with mud and debris, and there's about 60-90 minutes after the lahar alert for safe evacuation from the valley.

The network of roads around the mountain could be overwhelmed by a mass evacuation, potentially leaving people stranded in the danger zone. Emergency management experts said people need to plan on walking to safety. Another option is to drive to where they hit a roadblock or gridlock and then go the rest of the way on foot. What is critical is to plan it out ahead of time.

Three things people can do is sign up for emergency alerts on their phones, have a "go-kit" ready, and start evacuating the moment they hear the warning sirens.