An interesting parallel to today from the Mount St. Helens eruption is what happened in the city of Ritzville, Washington that was directly in the path of much of the ash. Many motorists coming back from Eastern Washington got stranded there because of poor visibility and up to six inches of ash on almost everything. They overwhelmed the city's facilities and were effectively quarantined within a school cafeteria. After two days a group of motorists tried to break the quarantine:

"So two days after the eruption, a large group of "rebel motorists" chose to ignore official warnings and try to make an escape from Ritzville. Most turned around within a few miles as they encountered nasty, gritty ground blizzards of ash. Some had to pull over when their clogged cars died. Police said didn't know how many cars made it out, but they said it wasn't more than 100."

Source: https://www.historylink.org/File/9398 (From History Link, a great free encyclopedia of Washington State history. Several states have projects like this online which are fun ways to learn about the history of small towns, how a particular region reacted to a large historical event, etc.)