That's just it. I can't think like that. Just because I don't see a way out doesn't mean there isn't one, I would try finding a way to escape untill I was dead no matter how hopeless it seemed. You never know what will come from trying untill you actually do it.
When the floor is burning your feet and you're choking on black smoke and the doors to the stairway are locked, you pretty much know that you're screwed. My understanding is that it was quite hideous on the floors just above the impacts and that people knew pretty quickly that they were doomed.