Thanks for confirming what I was speculating about upthread . . . and you're right about the danger of idle speculation . . . but now we know that yes, hundreds of people are in fact trapped in those attics, just as I feared . . .
I don't know about the electricity but some people just could make it out. I suppose they were hoping the attic would be fine :(
That's why the NOAA flood warnings at some point said to take axes to hack your way out of an attic or floor onto a roof.