I had a job delivering documents (for which I used my vehicle). One afternoon I had a little downtime between deliveries and not having had enough sleep the previous few nights, I fell asleep (I was parked). Upon awaking, I noticed the time and I was late.
So I sped to the next delivery, rounding a broad turn in the road and was passing someone on my left. This was in the USA so I should not have been passing in the lane to the right. The car on my left blinded me to a car that had just made a left turn from the other side of the road to go into a side street. Before I knew it, I was slamming on the brakes but it was too late and my speed too high. My mid sized pick up truck plowed into the passenger side of the turning vehicle.
My car was totaled. Neither my seat belt nor air bag worked, and my chest slammed into the steering wheel. Thankfully, I only sustained minor injuries. The passenger of the other vehicle was not so lucky. They died.