I don't think it will be Chernobyl or 9/11 level, but I do think an epic fuckup with potential casualties is going to set AI back ten years. And maybe by then we'll have figure out our shit enough to make it not destroy society.
It's the same cycle you see with deregulation. Dereg good, until so much dereg that something epically fucks up. Then it's "why did no one prevent this" and regulations are back again.