Either there was more than one, or this was the one that almost squished me :-/ there was a guy approaching the control from the other side at the time. Probably the scariest moment I've ever had orienteering.
I once had a big branch fall just behind me, while I was orienteering on a windy day. Very scary indeed.
It was a whole tree. I heard it cracking as I punched the control so I got the heck out of there. I couldn't tell which one was falling so I was running away looking over my shoulder to make sure I was out of the way. I was still close enough to get a dusty puff of rotten wood scented wind.
If the fellow looked like he had an Abe Lincoln-type beard, it was probably Clint Morse who told Glen about the falling tree he saw.