When entering the jail building upstairs room, beside the pair of bunks is a locker and a window looking over the runway. I was able to reproduce this by hitting X to crouch, then opening my inventory tab, then crawling between the window and the bunk. Finally, hit the C button to stand up and then Tab to close the inventory. Then I die. This has killed me twice, unless there is a remote possibility I was sniped twice with no gunshot sound. The second time it broke my legs and then killed me. It could be that standing up under the bunk is what kills you. I also died instantly once on top the school roof.