Two commuter trains collided and derailed during the evening rush hour outside Boston on Wednesday, trapping and killing the operator of one train and injuring several passengers, authorities said.
The crash came just hours after an elevated train derailed in Chicago, sending several people to hospitals in a wreck that officials quickly blamed on operator error.
Investigators did not know what caused the Boston wreck, which killed a woman and injured about 10 passengers in an above-ground accident on the city's "T" system near a station in suburban Newton.
The operator's body was still trapped in the wreckage late Wednesday, said a firefighter at the scene who spoke anonymously because he was not authorized to do so publicly.
The two-car train she was operating slammed into the back of another two-car train approaching Woodland Station, said Joe Pesaturo, a spokesman for the Massachusetts Bay Transportation Authority.
"The first one was stopped at a red signal and was ready to proceed to the station when it was struck," he said.
One passenger was flown to a Boston hospital, and the other injured commuters were taken to nearby Newton-Wellesley Hospital, Pesaturo said.
The hospital had eight train-wreck patients, none with serious injuries, said spokesman Brian O'Dea.
The train operator's father, Terry Jones, identified her as 24-year-old Terrese Edmonds, The Boston Globe reported. Firefighters struggled to free her body from the tangled wreckage.
Passenger Barry Gallup, standing aboard the train that was hit, told WCVB-TV that the impact threw him to the floor.
"I may have been knocked out for a few seconds. ... The next thing I knew I was lying on the ground," Gallup told WCVB.
He described a confused scene immediately after the crash, with some passengers screaming and small fires breaking out on the side of the train. Other passengers concurred about the chaos.
"There was a 70-year-old old guy who went ballistic, screaming at the conductor, 'You killed my wife! You killed my wife!' And the wife is going, 'I'm OK! I'm OK,'" passenger Matt Stone, 46, told The Boston Globe.
Federal investigators were on their way to the crash site, said Peter Knudson, a spokesman for the National Transportation Safety Board.
In Chicago, authorities said a train operator apparently made two key errors in quick succession to cause a derailment that left passengers perched more than 20 feet above the ground and sent several to hospitals.
The operator failed to heed a red signal ordering him to stop, Chicago Transit Authority spokeswoman Noelle Gaffney said. After the four-car train went through the signal, it automatically activated a trip, which stopped the train.
But the operator moved the train forward again at a spot where the tracks split before they were switched into proper position, causing the rear end of the front car and the second car to derail but remain standing, with the other two cars still on the tracks, Gaffney said.
"He was going on the wrong tracks, or started to," Gaffney said.
She said there was still a possibility the aging transit system played a role in the derailment, which sent 14 people to the hospital, none with life-threatening injuries.
Investigators were interviewing the operator, who has 31 years' experience, and he was cooperating, Gaffney said. He will undergo drug testing and not be allowed to return to work until the investigation is done.
The derailment jolted the passengers enough to cause injuries, as well as leaving them fearing for their lives as they remained stuck about 22 feet from the ground.
"I was just hoping that train didn't go over the edge. That was the only thing I was really concerned about," said 35-year-old Willie Jackson, who was aboard the second car. "If the train would have fell off the edge on to the ground, we probably would have been dead and hurt real bad."
Baker was one of 14 people taken to hospitals. Eleven were considered in good condition and three were in fair, said Fire Commissioner Raymond Orozco. A total of 25 people were on the train, including one CTA employee.
Some of the injured were put in ladder baskets and lowered to the ground, where they were put in ambulances. Others were led off the tracks via a nearby stairwell, officials said.
The derailment served as another example of problems for the city's deteriorating century-old train system, which runs throughout the city and to nearby communities on tracks both elevated and underground.
In the most extreme recent incident, a crowded rush-hour train derailed in a subway in July 2006, causing a smoky fire that injured more than 150 people, six seriously.
The National Transportation Safety Board in September issued a blistering report of the system, saying a seriously flawed inspection and maintenance program likely played a major role in the 2006 derailment.
Associated Press writer Don Babwin and AP videographer Mark Carlson in Chicago contributed to this report.