Cleanup work was continuing Saturday after a train carrying crude oil derailed Friday evening in Plainfield.
Roughly 20 tanker cars left the tracks about 6:54 p.m. Friday in an area occupied mostly by businesses at 143rd Street near Riverwalk Court.
No injuries were reported and there was no threat to public safety, but Canadian National Railway spokesman Patrick Waldron said about 40,000 gallons of crude oil leaked from three of the cars.
"A comprehensive investigation is under way to determine the cause" of the derailment, he said.
Plainfield police Cmdr. Ken Ruggles confirmed that the public was not in peril.
"The fire department sprayed foam onto the track and once that was done there was no risk," he said.
Crews stopped the leaks and contained the spilled oil, much of which flowed into trenches that were dug for a natural gas pipeline.
"The oil has not reached the (nearby) DuPage River and no waterways were impacted," Waldron said. "The cleanup is well under way."
Crews were using heavy cranes Saturday afternoon to set the damaged cars upright.
The railroad's hazardous materials and environmental response teams were helping coordinate the cleanup efforts along with the Federal Railroad Administration and the Environmental Protection Agency with assistance from Will County's emergency management agency.
The tank cars, the cleanup crew, the evacuation team, "everything worked like it was supposed to," said transportation expert and DePaul University professor Joseph Schwieterman.
"Derailments of crude trains are scary things," he said, "but the impacts of this one were lessened by the planning and preparation of everyone involved."
• Daily Herald staff writer Marni Pyke contributed to this report.