One man is in critical condition and another is in fair condition after a helicopter leased by Commonwealth Edison apparently suffered engine failure and crashed in Huber Park Wednesday.

Com Ed employee Robert West, 51, Rockford, Ill., was transported by helicopter to St. Anthony’s Hospital in Rockford, and is listed in critical condition. Pilot Leonard Jablon, 47, Northbrook Ill., was transported to Kishwaukee Community Hospital and is in fair condition. The two men were checking electrical power lines at the time of the accident.

DeKalb Police Chief Donald Berke said the crash is being investigated by the Federal Aviation Administration and the National Highway Transportation Board. Officials discontinued the on-sight investigation Wednesday night due to darkness and will resume their efforts this morning.

DeKalb Police provided security throughout the night to ensure no one would tamper with the wreckage or fuel scattered around the crash-site.

Reports from eye-witnesses and Jablon indicated that engine failure caused the helicopter to nose-dive into a wooded area on the north side of the Kishwaukee River directly east of the park’s footbridge.

The helicopter came to rest on its side after the cockpit’s bubble shattered from the impact, Berke said. There was no fire or smoke associated with the incident and both men were conscious, he said.

Berke said West and Jablon were extricated from the Hughes 300-C Schweizer helicopter by DeKalb firefighters. West was trapped in the wreckage for about 30 minutes as 14 firefighters and paramedics utilizing a fire engine, a rescue vehicle and two ambulances were at the scene for about two-and-one-half hours.

Berke said the low-flying helicopter was traveling north toward the Northwestern Railroad tracks when it circled back toward a clearing in the park and crashed. It is not clear if the pilot experienced a quick engine failure and was attempting a crash landing in the park’s clearing, he said.

The helicopter was leased from the Eagle Helicopter Service, Chicago.