When umpires fall

[voiceoflg]

At a tournament this past weekend, a batter hit the ball to right center. BU went out and PU went to the right of the mound. BR touches first and heads to second. PU falls face first, gets up to an all fours position and stays. The throw comes in to second and beats the runner. PU raises his right arm from all fours. It looked funny, but he stayed still to make the call instead of trying to stand up and possibly miss the call.

Have any of you had or seen a situation where an umpire fell during a play?