Explosion Door

That'll teach you to open doors.

This is when someone opens a door to a room that's filled to the brim with something and that said something falls onto them. In real life, Explosion Door might be next to impossible with a room that's too big, especially when it happens with a water-filled room.

Usually only Played For Laughs, Explosion Door is an exaggerated display of the sheer amount of something like water (as mentioned before) or money: the amount is so large that it could fill an entire room up to its door and beyond, burying anybody who opens the door under whatever the room is filled with.