This could really be anything.
Here’s something I experienced.
I was sitting at an intersection in the left turning lane at a red light. Someone in the crossroad (the road I was going to turn onto) was about to turn on the road I was on, they were in the middle of the intersection. The light turned yellow, then red, and of course, they decided to turn when it was red because they had no choice. At the exact same time, another car came flying through the intersection straight-on and slammed into the car that was turning — barely 20 feet in front of me. The car that was turning was t-boned and was sent slamming backwards, hitting the pole of the stoplight, and the car that hit them was stopped in the middle of the road, the entire front of their car crushed.
I was on my way to work, so I had to leave. Everyone was okay; the person who got hit was extremely angry, even if they were at fault. But that was the first time I witnessed a bad accident first-hand.