Are there no elevators in this building? I mean, if you toss a bloke (well, two blokes) over the banister, he’s way going to beat you to the bottom if you can only exit by the stairs. How do you get out of the murder scene? Run screaming down the stairs ‘OMG he fell!’ ?
It’s hard to imagine a building with a 17+ floors not having elevators. And almost as hard to imagine people who have reason to be on the 17th floor not using the elevators instead of the stairs. Possibly the stairs are used for short trips — maybe faster to get from 16 to 17 by stairs than waiting for an elevator. But still . . .