Updated

A commuter train derailed Saturday on Chicago's South Side, killing at least one person and injuring 83, officials said.

The five-car Metra (search) train was traveling from Joliet to Chicago when the derailment occurred around 8:36 a.m., authorities said.

The Cook County (search) medical examiner's office confirmed the fatality but did not have details. Seventeen of the injured were in serious or critical condition, said Assistant Deputy Fire Commissioner Raymond Orozco.

A total of 189 people, including four crew members, were on the train.

Metra spokeswoman Judy Pardonnet said all track signals were working when the derailment occurred but she did not have any other details on a possible cause.

The speed limit there is 15 mph, Pardonnet said. She said she did not know how fast the train was going.

The engineer has been operating Metra trains for 45 days, following six months of training that included trial runs on the same Joliet-to-Chicago route and more than five years as a CSX Corp. (search) freight train engineer, she said. The engineer, who was "badly shaken," was taken to a hospital for routine drug tests.

The derailment occurred where the tracks are on an embankment next to a street in a neighborhood of homes and businesses. None of the cars fell onto the street. Firefighters had to raise ladders to the track.

Karen Birkeland, of Chicago, who was in the second car, said there was no warning.

"The train rocked and slowed down and stopped," said Birkeland, who was traveling to her office in Chicago's Merchandise Mart. "We were tilting to the side."

Stephanie Smith, who was sitting in the second car in the upper tier, said she heard brakes screeching before the train came to a halt.

"I just went flying into the safety seat bar and fell to the ground," Smith, a master's student at DePaul University (search), told the Chicago Tribune. "We were skidding out of control. Weaving back and forth. People were weeping and screaming."

The engine ended up on its side and there was a 30-foot gap between two of the cars. The remaining cars remained upright but went off the tracks.

There was another accident nearby on the same line two years ago, but Pardonnet said that may have been just a coincidence. "I don't think it's anything specific to this area, but it's still under investigation," she said.

Dozens of emergency vehicles and two medical helicopters were at the scene and workers erected three red emergency triage tents to treat people near the tracks. City officials asked for assistance from suburban emergency response teams, said Fire department spokesman Larry Langford.

Federal authorities would lead an investigation into the cause of the accident, said Monique Bond, a spokeswoman for the office of emergency management.