I used to work out in the Black Hills during the Sturgis motorcycle rally, and I would see a fatal accident almost every day.
One time I was the first responder; the guy was intoxicated or otherwise impaired, just drifted right into the guardrail and flipped over the handlebars. The hike kept going down the road for a quarter mile. The other staffer and I stopped our van and put the hazards on, gave first aid until an EMS tech showed up; this was before cell service was reliable in the mountains. The guy had a huge gash across his chest and had landed on the end of a cliff, a strip maybe a yard wide between the guardrail and a fatal plunge. He was still alive when we left the scene.
That was one of the milder accidents.