I saw that (or rather heard, and then turned around to see that had happened) on Riverside Drive in NYC once, not at a stoplight, but just after letting some passengers off at one of the bus stops. Bus was pulling away and then... whooompf! People had to climb up and exit to the rear, as the back door was still above street level, fortunately. It was quite startling, even though I was not on the bus.
All the freakin' fires popping up in my neck of the woods 😕
Yes I hope everyone in smoky-CA will stay safe, what a horrible situation and now so unpredictable.