Where were you when this happened (if you are over 50 years old)?
Many working in emergency management now were likely either not alive or not cognizant of national events -- like volcanoes erupting. I was in Wisconsin, getting ready to deploy to Germany when I saw the pictures and video on the national evening news. I thought, "Wow, I didn't know we had volcanoes in the United States!
KING TV has a retrospective on the events/timeline leading up to the eruption. Put yourself in the place of state and local emergency managers at the time. There was a two-month lead-up to the big blast. As I wrote recently, someone's quote, "Predictions are harder to do for future events."
As I recall, the area that was cleared of people had been relaxed due to the lack of activity from the mountain. So loggers and others were allowed back into some areas. Not the best decision in retrospect, but compare it to people clamoring today for the economy to open up due to the COVID-19 virus ... what will happen next?
Back then, they were reacting to the "fog of the volcano" and today it is the "fog of the virus." I'd rather be damned for being too careful. Dead people wear on my conscience.