CHICAGO (CBS) — A person died after diving under a carnival ride in west suburban Naperville.

The man was attending the annual Ribfest on Thursday when he jumped in front of the Pharaoh’s Fury attraction, in which riders are swung back and forth like a pendulum.

The Naperville Police Department tweeted that the incident appeared to be an “intentional act” by the victim. A death investigation continued.

Witnesses say they saw the man dive underneath.

Lisa Wojtiechowski told CBS 2 that she felt a bump and saw the man’s legs as the ride went over him. Another rider, Amanda Pereira, said the ride struck the man a few times before it could be stopped.

That part of the Ribfest was closed as of 4:15 p.m. while the coroner investigated. A large green tarp covered one end of the ride.

Other areas of the festival remained open.