ROCKFORD, Ill. — A freight train hauling ethanol derailed and its tankers exploded, killing one person and triggering a fire that continued to burn early Saturday.

Officials evacuated the area on the edge of Rockford, about 80 miles northwest of Chicago, Friday night amid concerns about air pollution and the chance that more of the train's cars might catch fire.

Winnebago County Coroner Sue Fiduccia said early Saturday the death was that of a female who had been in a car that was waiting for the train to pass a crossing near the derailment site. Fiduccia would not release the victim's name or age.

Rockford Fire Chief Derek Bergsten said three other people from the car ran from the vehicle when it was bombarded with flying railroad ties and were severely burned by flaming ethanol from the explosion.

The three were taken to OSF Saint Anthony Medical Center in serious to critical condition, and one of them was later airlifted to Stroger Hospital in Chicago, Bergsten said.

The fire chief said the eastbound Canadian National train had 114 cars, 74 of which were tankers filled with ethanol.

Witnesses told the Rockford Register-Star that cars on the Chicago-bound train began hydroplaning in standing water just as it approached the crossing. Some of them left the tracks moments before two of them exploded.