I was in my house and was coming back from the garden jumping and managed to do a triple jump. Observing on the trajectory I was thinking that maybe I wont hit the house wall on the way down - but close call. Maybe I did in the end no idea, but in the end I landed below the floor. Could not jump back out, though I could walk to the door and click it to get elsewhere.
http://www.glitch.com/snaps/PUVEQGRPHDH27AS/134611-e0f11b34ca/