More than 30 people were injured early Monday in Chicago when a commuter train derailed and barreled up an escalator at a station at one of the busiest airports in the United States.
Some of the people injured in the incident at the O'Hare International Airport station were taken to hospital while others were treated at the scene, a spokeswoman for the Chicago Transit Authority told AFP.
None of the injuries were life-threatening.
"The train did not decelerate and went past where it should have stopped," said the spokeswoman, Lambrini Lukidis.
The Blue Line train crashed just before 3:00 am -- a relatively quiet time at the airport. The transit authority said the train had roughly 50 people on board.
The CTA and the National Transportation Safety Board were to investigate the incident.
"It's too early for us to be able to speculate what happened here," Lukidis said.
The station was temporarily closed to clear the wreckage. Commuters were to be bussed to and from the airport.
In September, up to four dozen commuters were injured when a CTA Blue Line train crashed into another at a suburban Chicago station.