The National Transportation Safety Board sent two people to Walnut Creek to take over the investigation of a double fatality on the Bay Area Rapid Transit (BART) tracks Saturday afternoon.
A train struck and killed two BART employees on the tracks near the Walnut Creek station at 1:52 p.m.
A federal investigator says the out-of-service commuter train that struck and killed two San Francisco Bay area transit workers did not have a front-facing video recorder that would help reconstruct the moments leading up to the accident.
But National Transportation Safety Board investigator Jim Southworth told reporters Sunday that interviews, equipment inspections, audio recordings and a video showing part of the train's cab should provide enough facts to determine what caused the mishap.
Southwork says that even if the strike ended immediately, the ongoing investigation means it would probably take a few days before trains could run on those tracks.
They were struck on the second day of a labor strike by two of BART unions.
The two men died at the scene. Video showed one body covered in a yellow tarp on the train track and a second body covered and laying on the side of a short hill. The bodies were about 150 yards apart.
Word of the deaths brought BART's general manager Grace Crunican to the scene. She said the entire BART family was grieving Saturday night. "This is a tragic day in BART's history," Crunican said.
BART said the workers were performing track inspections in response to a report of a dip in the track. The train had been moved initially to remove graffiti.
Union officials have identified the victims as Chris Sheppard of Hayward and Larry Daniels of Oakland. Sheppard used to work for Amtrak.
The NTSB said it will be at the accident scene for at least four days.
President of AFSCME Local 3993 Patricia Schuchardt said one of victims was a member of the AFSCME union, which is not on strike.
“We are saddened to learn that two BART employees were killed today after being hit by a BART train. One of the employees was a member of AFSCME Local 3993. Our hearts go out to the family of both workers as well as to the person operating the train. This is a tragedy,” Schuchardt said in a statement.
"Both people had extensive experience working around moving trains in both the freight train and the rapid transit industry," BART said in a separate statement. "The procedures involved in track maintenance require one employee to inspect the track and the other to act as a lookout and notify of any oncoming traffic."
An experienced operator was at the controls, according to BART, but at the moment of impact the train was being run in automatic mode under computer control.
BART employees were on strike Saturday, but some trains had been moving between stations for maintenance and security reasons, a BART spokeswoman said Friday.
BART management and union officials have been at an impasse over contract negotiations since Thursday.
One of the unions on strike, Amalgamated Transit Union 1555, announced that its 900 workers would not be picketing on Sunday out of respect for the victims and their families.
Spokeswoman Luna Salaver told Bay City News Friday that the trains are running to make sure the tracks do not rust and everything is in working order. She said all maintenance and security work was being performed by a small group of non-union staff members.
BART police Deputy Chief Ben Fairow told NBC Bay Area the accident happened adjacent to Jones Road at North Main Street in Walnut Creek. He said the area was being treated like a crime scene and per protocol, the train operator will be drug tested.
The Associated Press contributed to this story