Rick Benson, EMS director, said after the concert was over at 10:30 p.m., Nickels was not feeling well. As rescue personnel assisted him, Nickels suffered cardiac arrest.
Benson said CPR was performed and Nickels was transported by ambulance to Jennie Edmundson Hospital, where he was later pronounced dead.
Council Bluffs Police Criminal Investigation Division Sgt. Ray Mabbitt said investigators are still trying to determine where Nickels is from. Mabbitt said an autopsy was scheduled for today.
Friends said that Nickels had a family history of heart problems, Mabbitt said.
Benson said medics treated nearly 30 people for minor injuries at the concert, which featured mosh pit dancing.
In 2005, law enforcement made two arrests at a Slipknot concert at the MAC after the crowd rushed a door that was to be used to enter the main floor of the arena before the show. When officers arrived, audience members were trying to ram the doors with a table.
While officers tried to push back the crowd, one person allegedly instructed others in the crowd to rush the police and people began throwing things at the officers. Pepper spray was used to try to disperse the crowd, and a TASER was also used after someone threatened an officer.
