[michelb]

If you have no roof access from the attic, and the water level rises, you are stuck.

[mnw21cam]

Rip away the roofing felt, shove the tiles, then you have a hole. Climb out.

[wiredfool]

After you've gone through the 3/8"-3/4" plywood/osb that's nailed on well enough to not come of in a hurricane?

[michaelcampbell]

My attic at least has several layers of plywood between the airspace and the felt. Probably why you see footage of rescue teams trying to get to the attic from the outside... with axes.