At least 32 people were injured, none seriously, when an eight-car train crashed through a barrier at the end of the platform and jumped up an escalator at O'Hare International Airport on Monday, according to Chicago's Transit Authority.
Six people were listed in fair condition and 26 in good condition at three area hospitals, according to fire officials. None are believed to be life-threatening.
The train derailed around 2:50 a.m. as it was pulling into the O'Hare station, Chicago Fire Commissioner Jose Santiago said at a morning briefing.
"The train actually climbed over the last stop, jumped up on the sidewalk and then went up the stairs and escalator," Santiago said.
Chicago Transit Authority spokesman Brian Steele told reporters that authorities are trying to piece together what happened, but says the train was likely traveling too fast.
"We will be looking at everything — equipment, signals, the human factor," he said.
Service on the Blue Line was still suspended between O'Hare and Rosemont as the morning commute began, according to transit authority alerts. Buses were being used to get passengers to and from the airport.
The Chicago Transit Authority began a four-year, $492 million track overhaul on the Blue Line earlier this month.
Contributing: Donna Leinwand Leger; Associated Press