Diving bell, confined spaces, closet
This is a character exercise.
The players each get onto an elevator at different floors. Each character uses the step of getting on the elevator as a vehicle for demonstrating their characteristics. Without speaking the character should be clearly defined by how they move, how they push the call button, and what noises they make. The next character on should make a choices that compliment the character that is already on the elevator. These characters all interact as they see fit. Keeping in mind the confined space of the elevator, and the eventual need to exit. It is important that all the players accept and help define the environment of the elevator.
Have the elevator break down and leave them stuck in it for some time.