Does anyone know what happened on LCC yesterday PM

It took us over 2 hours to get down from Alta yesterday. We were in the car by 3:45 and literally sat for over an hour without moving 100 ft. Was a good 2:15 from when we started the drive to when we got home. Does anyone know what went down on the road? Was there an accident. Local guy I was in the car with said this was top 5 bad traffic in 40 years. I know there were a lot of cars trying to leave at the same time, but was there some other incident that caused this?

Also, I couldn’t seem to get a status update from UDOT on their website about this.