Why are the police blocking all the on ramps to 45?

I was driving to the med center and I saw the police blocking multiple on ramps around the 40–46 range. After exiting at 46B they were continuing to block more entrance ramps.

Once I got into the med center even more streets were shut down. I’ve seen easily 50+ police in the last 15 minutes.

I’ve been looking everywhere but I can’t find anything about this. Does anyone know what is going on?