Looking 49 Floors Down a Fire Tower

Title pretty much says it all.

It's a 10'x16' hole running through a large office building in Midtown. Back in the days before sprinklers, they used to create a vestibule before you entered the egress stair. The vestibule has a railing and opening into the "fire tower." The idea is to be able to vent smoke from a floor on fire without contaminating the egress stair.

I can tell you that this thing works like a giant straw and even the slightest breeze blowing over the top of the shaft creates some serious negative pressure; meaning it's very hard to close the vestibule door after you've opened it.