Head on collision between two pickups about twelve years ago. Late night, pretty empty road. I was on a bus waiting at a red light with two other people and the driver. The drivers of the pickups were in about the best state you could expect, battered but not broken, but the one pickup had a passenger and she was... ugh. There wasn't much the few people trying to help could do: somehow her left arm had been nearly torn off at the shoulder or something had cut right into the area, her legs appeared to be crushed, her face had been struck very hard by something. She was still alive when emergency services arrived, but was totally unresponsive and there was blood everywhere. The way her arm/shoulder was injured coupled with her being stuck in the vehicle made it impossible for us to stop the bleeding.

I kept the stained clothes I was wearing that night for a few days. I kept staring at them. I'm not sure why.