And you are where? I’d be suspicious, and I’d be locking extra doors and maybe even posting guards at the one door that opened out. Safe > sorry. Esp as it has happened 3 times.
Wise as serpents, gentle as doves.
Yes, minimize the outside access to doors that have heavy traffic. Alarm the locked doors if possible and post no exit signs on them. Or just post no exit on the extra doors—no barricades—in case of real emergency.