Eli5: How so firemen rapidly know the layout of large buildings in places like NYC during a large fire or emergency?

Question

Edit: Thanks for the folks that are in adjacent areas that got back to me and were kind, I was just curious as a laymen New Yorker.

UPDATE: One of my friends got back to me I guess they have blueprints and do drills and do drills and shit and that I’m not allowed to know the rest – whatever bitch tits, comments basically stated that

In: 75

Answer 1

Pre-planning. Paid departments have time, money, & manpower to assess a new building and then develop a training plan for it. Sometimes they train at the building.