This didn't happen to me, but to someone else on my team.
We had assigned one of our sophomores to start cutting wood for the bumpers. Her tool of choice was a handheld jigsaw. She wasn't wearing safety glasses, despite the fact that the safety captain was standing right next to her.
I'm sure you're expecting something to come flying out of somewhere right now...
Thankfully, she didn't have to learn to wear safety glasses the hard way, but her untied hair did get stuck in the jigsaw motor.

She luckily escaped unscathed (minus some hair). This should serve as a reminder to keep all long/loose items like hair, jewelry, clothes, headphones tied back or out of the way.