Earlier, cleanup crews said they found the bumper of a car in the wreckage.
Investigators are now trying to determine if a car was underneath a bridge that collapsed during Wednesday's derailment near the border of Glenview and Northbrook at Willow and Shermer roads.
Thirty-one cars went off the tracks. Investigators are trying to figure out if heat played a role. Investigators think the bridge collapse happened after the train went off the tracks.
A Union Pacific spokesman said the cleanup and road repair will take a few days. It will take longer to fix the bridge.
The derailment does not affect Metra trains.
ABC7 will have more information on the news at 4:30 p.m.