Here's what I propose. We give things perhaps a day, to let everyone get their characters to the point they feel comfortable really kicking things off. At that point, we...kick things off. I propose that we combine "school canceled because of no power" with "timeskip", but make the skip one of, perhaps, half an hour.
Actually...hm.
See, the kicker is, with the teachers still around, there's really no need for the kids to get involved. Unless something pretty much forces all the teachers who have powers away to deal with something else. As soon as that happens, our amateurs with powers can intervene.
Thoughts?