A freight train ran a red light moments before Tuesday's deadly crash with a commuter train, but investigators stopped short of blaming human error.

"There is no question the Burlington Northern train should have stopped," National Transportation Safety Board Chairwoman Marion Blakey said Wednesday.

Two died and more than 260 were injured in the crash during morning rush hour. Some Metrolink passengers were thrown from their seats; others clambered out windows of the double-decker commuter train.

Blakey said the freight train rolled through the signal at 48 mph, hitting the commuter train, which was stopped at the crossing. Investigators found no problems with railroad signals, equipment or the tracks, she said.

The freight train began braking about 1,700 feet before the crash, and had slowed to 20 mph at impact. The Metrolink engineer saw the other engine coming and halted the commuter train, Blakey said.

"He did have time to leave the cab to proceed toward the back of the first car and warn the passengers," she said.

Investigators are interviewing crew members of both trains and pulling personnel records and work schedules. "We want to look particularly at that 72-hour window before the crews came on duty to see what may have factored in in terms of their performance," Blakey said.

Burlington Northern Santa Fe spokesman Richard Russack withheld comment on the agency's findings.

"We have participated fully with the NTSB in the investigation so far and we will continue to participate and we will wait until the final report is produced before we make any further comment," he said.

Killed in the crash were Robert Kube, 59, of Moreno Valley, and Lawrence I. Sorensen, 48, of Riverside. About 162 people were taken to 10 hospitals, said Orange County Fire Authority Capt. Steve Miller. Of those injured, 19 were described as serious. About 100 others were treated at the scene.

After the commuter train halted at the crossing, some riders, apparently thinking the train had reached its next station, stood up, according to passenger Bill Marin, 50.

"The people who were standing seemed to be the worst injured," he said.

Dan Veenbaas, 49, was among passing motorists who jumped aboard the train to try to help the injured. He found people lying on the floor and slammed against seats.

"It was pretty horrifying," he said.

Jackie Bisesi, another witness, said the passengers tried to aid one another. "All the people getting off the train were bloodied and they were still trying to help each other," she said. "There were people who got on to the roof of the train and were trying to pull people out."

NTSB investigators believe the freight train's brakes were working properly, Blakey said, adding that the train's crew applied them 2,100 feet before the crash.

The freight train's crew -- an engineer and conductor -- jumped from their locomotive just before the accident. Blakey said drug and alcohol tests were given to the train crews and the dispatcher on the route, as is routine after a crash.

NTSB investigators retrieved the event recorders that provide mechanical data on the trains, such as speed, braking maneuvers and use of horns at the time of the crash. Recorded radio conversations between the dispatcher and the crews also will be analyzed, Blakey said.

Russack said the freight train was en route from Los Angeles to Clovis, N.M., and carried 67 loaded containers. The train company owns and maintains the stretch of rail where the crash occurred.

Southbound Metrolink 809 was traveling from Riverside to San Juan Capistrano on a route that has 12 trains and 3,000 passenger boardings each day.

The accident was the worst in the nine-year history of Metrolink, a commuter rail service that carries 32,000 passengers on 128 trains daily. It also was the nation's second deadly train wreck in less than a week.

Freight traffic through Placentia resumed early Wednesday, while passenger service was to be restored shortly after noon.

For the morning commute, while the tracks were still closed, Metrolink offered travelers free rides on a caravan of tour buses.

As one bus neared a station near the crash site, longtime commuter Cynthia Smith-Barnes said her husband used to work with one of the men killed in the wreck.

"I think they do their job with competence," she said of railway workers. "Now if they can just figure out what happened to avoid it from happening again."