A worker trying to dismantle a ride at the Six Flags Great America amusement park north of Chicago died after falling more than 40 feet.

Officials say 46-year-old Thomas Lee of Pleasant Prairie, Wisconsin was part of a crew taking apart the Splash Water Falls ride at the theme park in Gurnee when he fell.

Lake County Coroner Richard Keller says Lee suffered head and chest trauma in the accident.

Keller says the U.S. Occupational Safety and Health Administration has launched an investigation.

Gurnee Fire Department Battalion Chief Bob Heraver says Lee was on top of the structure with a crew of about six to eight workers when the accident happened. He says nobody saw exactly what happened until it started to happen.