Buster Keaton’s most famous stunt was in ‘Steamboat Bill Jr’ (1928). The wall of a house falls on Keaton, but he isn't hurt because he is standing exactly where an open window lands.
Robin Williams was a comedian in stand-up comedy shows. He became famous as a comedy actor in his "Mork and Mindy" TV series and was hilarious in many movies -- like "Mrs. Doubtfire!"