LOS ANGELES, Sept. 12 (Xinhua) -- At least 10 people were killed and 70 others injured on Friday when a Metrolink commuter train slammed into a freight train near a Los Angeles suburb, authorities said.
The death toll was continuing to rise, Mayor Antonio Villaraigosa told reporters at the scene.
"The latest figure that we have is that there's somewhere in the neighborhood of 10 to 15 fatalities," Villaraigosa said. "This is probably the most serious train wreck to occur here in a very long time."
Previous reports said at least six people were killed in the collision.
The Metrolink train carrying about 400 passengers crashed with the freight train in the Chatsworth area, some 50 kilometers northeast of downtown Los Angels, around 4:00 p.m. local time, setting off a massive rescue effort and search for other possible fatalities.
At least seven cars from the freight train derailed, although most remained standing in accordion fashion across the tracks.
Fire crews swarmed to the scene and into the overturned Metrolink train, pulling injured passengers from the wreckage and escorting them to makeshift triage centers.
The interior of the train was "bloody, a mess. Just a disaster. It was horrible," passenger Austin Walbridge told Television Station ABC7.
Officials expect the death toll to mount as hundreds of firefighters and police officers were trying to rescue those trapped in the wreckage. Some passengers had blood splattered across their faces as they huddled on the ground, tending to their own injuries as they waited for busy paramedics to reach them.
Eleven people, five of them in critical condition, were taken to Providence Holy Cross Medical Center, according to ABC7.
As the rescue operation continued into the night, a sea of lights illuminated the scene to guide firefighters through the twisted wreckage.
Metrolink spokeswoman Denise Tyrrell said it was unknown exactly how many people were aboard the Metrolink train, although the train could carry between 350 to 400 people.
The cause of the crash remained a mystery, as the Metrolink train and the freight train wound up on the same track at the sametime -- with deadly results.
"We have absolutely no information along those lines," Tyrrell told ABC7. "That's just not our goal right now. Right now our goal is the safety of the people on that train."
The Los Angeles Police Department declared a citywide tactical alert in response to the crash.
As the death toll continued to rise, the crash threatened to become the deadliest in the 16-year history of Metrolink.
The deadliest crash in the system's history occurred Jan. 26, 2005, when 11 people died and dozens were injured when a Metrolink train slammed into a Jeep Cherokee that had been parked on the train tracks in Atwater Village near Los Angeles. The train derailed, struck another train traveling in the opposite direction and hit a freight train.
That derailment was the deadliest U.S. train crash since 1999.