A Wednesday evening collision between a Metra commuter train and several vehicles at a grade crossing in Elmwood Park, Illinois, injuring at least sixteen people.

Three people were in critical condition, according to Judy Pardonnet, a spokeswoman for the Metra train service.

Witnesses and bystanders say that multiple cars had victims trapped after a chain reaction effect occurred from the original impact at approximately 17:00 CST. The rail crossing where the accident happened cuts through a busy diagonal intersection, and a street sign above the tracks reads: "Long crossing. Do not stop on the tracks."

The Wednesday evening collision apparently was the result of heavy traffic congestion that did not allow ample times for vehicular traffic to vacate the crossing once gates were activated. According to witness reports, motorists did not head the warning not to stop on the tracks. The initial impact occurred after the gates had properly activated and the Chicago-to-Antioch Metra train impacted 'several' cars.

Of the injured, three were aboard the Metra train and thirteen were from motor vehicles. Two women were listed in serious condition at Loyola University Medical Center in Maywood, spokeswoman Anne Dillon said.