According to, police have opened an investigation into the death of a 62-year-old man during a SLIPKNOT concert in Tinley Park, Illinois last Sunday (August 11). Foul play is not suspected, police said.

Witnesses told that Richard Valadez joined in some of the mosh pits that formed in the lawn section of the “Knotfet Roadshow show at Hollywood Casino Amphitheatre and was knocked to the ground at least once.

About an hour into SLIPKNOT‘s set, he fell out of the pit and into the grass. As people were trying to help him up, he suffered a seizure and witnesses called for help. Two men performed CPR on him before staff and emergency personnel showed up to assist Valadez.

Several witnesses described confusion at the scene, which led to a delayed response from medical personnel.

Valadez was pronounced dead at 11:34 p.m. CT on Sunday at St. James Olympia Fields Hospital.

Valadez‘s sons, Richard Valadez, Jr. and Andrew Valadez, said they have been told their father may have died as a result from a heart attack. However, they said, they’re wondering whether he might have survived that if he had proper or quicker medical care.

“A lot of things were going on and it appears that nobody had any type of control, I don’t think,” said Richard Valadez, Jr. “I just want some answers.”

Tinley Park was the second time in less than a month that a SLIPKNOT concert has allegedly become violent.

In late July, SLIPKNOT frontman Corey Taylor was reportedly forced to stop the band’s concert in San Bernardino, California after fans were being trampled and suffered seizures in the mosh pit. In an attempt to make room on the floor for paramedics, Taylor told the crowd: “No one is fucking getting hurt on my fucking watch. Do you understand me? Back the fuck up!”