Did a HVT mission, was sent into a storage building, consisting of two big storage rooms.
Fought my way through both of them, killed the boss and "triggered the trap". after killing the boss, a rolling gate went down and locked me in on the far side of the building, without an exit.
That brave cleaners sacrificed themself to lure me into that trap to lock me inside the building. Unfortunately they did not know my ability to fast travel and escape that deathtrap.