cursed machines

This morning i was mawing the lawn and suddenly something shooted out of the machine it was this square piece of wood. It flew thru the air with an incredible speed and then hit my head right above my glasses.... (after that i fell down and when i tried to get up everything was twhirling around me).

Anyway did any off you guys ever had this thing or another strange/dangerous experience with machines.

Btw i remember myself saying in some thread about nitrogen cooling that a cooling fan is dangerous because it can fly thru the case and hit you in your balls or legs (and then someone said that is would be impossible, but after this morning i think it really can)

::edit::
he LOL i just saw that there is also another recent thread about machines (what are the chances...)
::edit::