The sold out concert performed by electronic mix master "Bassnectar" is like a rave.
Music, lights, and dancing don't stop till the end of the night.
Around 11 o'clock, that's when police say problems began.
Officers dealt with many people who'd overdosed on drugs such as ecstasy, acid, and even bath salts.
"They were basically trying to restrain people for their own health and safety," said Lieutenant Tim Stanesa. "They were psychotic, they were out of control. In one instance we were concerned about one gentleman running into traffic."
One officer got hurt while trying to keep problems under control.
This is the second time "Bassnectar" played Bloomington.
Police say last year concert-goers weren't so out of hand.