[2.2.8] You can get 'crushed' if you jump at the ceiling while inside a Quicksand FOF.
If you jump at the ceiling while inside a Quicksand FOF, there's a chance that you will get 'crushed'. I first encountered this in a map that I was working on where I died while jumping at the ceiling a few times.
This can also occur in CEZ1. There's a mud pool that you can sink into to go through a tunnel that holds an Extra Life Box and if you jump around the ceiling there... you might get 'crushed'.
Test map that was use for capturing the first gif.