There's a similar issue with lifts (err, "elevators" if you're American). Nowadays they are often designed to discourage self-rescue in emergencies, because apparently if you get out you invariable fall down the lift shaft. The World Trade Centre lifts were of this sort, and I've seen estimates that they contributed to around 10% of the 9/11 deaths in those buildings.

I rarely travel by subway train but sometimes use lifts, and getting stuck in one during a powercut is one of my nightmare scenarios. I recently bought some Prybabies and I'm considering EDCing one in the hope that it would help. I'm not scared of lift shafts <img src="/images/graemlins/wink.gif" alt="" />