A friend of a friend friend just had a fluke crash like that. She was riding along she said with no one around, nothing special, on the flat, then she said she thinks something got in the wheels. I know for a fact that that road's shoulder can be a minefield of twigs, tree branches and other debris.

Fortunately some motorists stopped to help her, and got her emergency help. The ER tests showed she had a concussion and some brain hemorrhage. So glad she was wearing her helmet, but she was, as she does every ride. It saved her from worse, for sure.

Fortunately, I believe she is recovering well, but it will be a while before she is recovered enough to ride again. She is also facing the fear of riding again esp., in our hilly area.