Good gov site
According to PBS, Mt. Rainier is America's most dangerous volcano...
Paths of Destruction: The Hidden Threat at Mount Rainier
Official release about today's test:
On Monday March, 5th at noon, Pierce County Emergency Management will test the 17 outdoor lahar warning sirens in the Puyallup River Valley. This is a monthly drill that takes place on the first Monday of the month. A Pierce County Alert will be launched at 9:00 on Monday morning to citizens who have signed up to receive informational messages.