Last winter in Connecticut we had to evacuate our building because of snow load on the roof that was causing deformation of the roof trusses. It wasn’t on the order of a fire drill, but they wanted us packed up and out of the building within a half-hour or less. I think a lot of people in our area faced similar situations. (And there were a number of building collapses due to excessive snow load.)
Other than that, no “for real” evacuations other than fire drills a couple of times per year, which are taken seriously here. “Everybody out”, and we’re timed on the evac. The building is checked by security for stragglers before we’re allowed back in. We don’t fool around with fire drills – until we get to the parking lot / assembly area.