During a Slipknot concert over the weekend, a man died after reportedly collapsing near the show’s mosh pit.

The 62-year-old man, Richard Valadez, was attending the concert at the Hollywood Casino Amphitheatre in Tinley Park, Illinois and was participating in a moshpit – a common occurrence at metal gigs. However, according to The Independent, witnesses saw Valadez fall down into the grass next to the moshpit about an hour into the band’s set. He went into seizure and nearby witnesses called for help. After being taken to a hospital, he was pronounced dead Sunday night at 11:34 p.m.

Valadez’ cause of death is still pending as of Thursday afternoon, the Cook County Medical Examiner’s Office said. It is unclear at this time if his time in the mosh pit had anything to do with his death.

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Slipknot, the heavy-metal group known for tracks like “Before I Forget,” “Solway Firth,” and “Duality,” was performing as a part of their Knotfest Roadshow headlining tour. Some of the band’s mosh pits get a little too intense; frontman Corey Taylor told his fans during a show in July to back up after the mosh pit started to get out of control, warning that he would not begin the next song until things calmed down.

The group also played in their home state recently at the Iowa State Fair. While students from the Iowa’s chapter of the National FFA Organization usually volunteer during the show to help concert-goers find their seats and answer questions, FFA coordinators and Iowa State Fair security pulled the students from the concert before Slipknot started the show out of caution, the Des Moines Register reports. With the record-breaking 17,032 concert-goers and thousands of general admission tickets, safety concerns grew. However, the concert went on as planned and organizers said it was “not a bad crowd.”