It seems to be more that houses in the USA were being built cheap and burn down easier. While Europe obviously had the same issue with fires (looking at you Brugge - how often do you wooden town need to burn down, until you place a fucking stone?), but they approached it with better, fire proof materials - like bricks instead of wood.

The regulations in the USA seem to include those zig-zag stairs (probably I mixed up the name), where 2 stairways are on the same place, cross crossing each other.
In case of smoke/fire or demolition of this block, I don't see how those 2 stairs make a better exit, when they are in the same place.