WALNUT CREEK -- Federal investigators arrived in Walnut Creek on Sunday to begin inspecting the railway where a BART train struck and killed two workers on Saturday, the second day of a worker strike that has closed the transit agency to commuters.

Officials with the National Transportation Safety Board walked the tracks near Jones Road, requested video and signal data from BART, and took measurements at the start of what promises to be a lengthy investigation.

The names of the two workers were not released Sunday. They are the seventh and eighth BART workers to die on the job in the transit agency's 41-year history.

A BART police officer looks along the BART tracks along Jones Road in Walnut Creek, where a moving BART train struck and killed two people in Walnut Creek,
A BART police officer looks along the BART tracks along Jones Road in Walnut Creek, where a moving BART train struck and killed two people in Walnut Creek, Calif., on Saturday, Oct. 19, 2013. (Dan Rosenstrauch/Bay Area News Group) ( DAN ROSENSTRAUCH )

"We will be looking at everything, from the operations to the signals to the records that were kept," investigator Jim Southworth said, adding that he and the NTSB's Richard Hipskind are the two lead investigators into the transit workers' deaths. "This is going to be a thorough investigation, and it's going to take a long time."

NTSB was assembling a team of experts tasked with combing through piles of documents, performing mechanical inspections on BART equipment present during the accident and interviewing transit employees.

Inspecting a 'dip'

Video from a camera facing the cab of the train has also been requested for review, Southworth said. There was no camera facing outward from the front of the train that hit the workers, he said.

The four-car train was moved from the accident scene at 3:45 p.m. Sunday.

Southworth estimated that the investigation will take four to 10 days, with a final report and possible recommendations released in as early as six months. BART police and officials from Cal/OSHA and the California Public Utilities Commission also were at the scene Sunday.

The workers were struck around 1:53 p.m. Saturday, less than 48 hours after BART union workers went on strike and train service shut down. The two workers were on the tracks on the Pittsburg-Bay Point line, between the Pleasant Hill and Walnut Creek stations. Their deaths happened where the tracks run parallel to Interstate 680 and Jones Road, near Chandon Court and Pimlico Drive.

The two were inspecting the track after reports of a "dip" in the rail, BART Assistant General Manager Paul Oversier said Saturday. Both workers had extensive experience working on the track, he said. A BART manager was returning a train to the Concord yard after delivering vandalized cars to Richmond for cleaning, Oversier said.

BART officials said Saturday that one of the workers was a BART employee, and officials at AFSCME Local 3993 confirmed he was a member of the union.

BART union members went on strike less than 48 hours before the accident, but members of AFSCME are free to cross the picket line, AFSCME president Patricia Schuchardt said Saturday. Those workers were encouraged to "stand in solidarity" with others on the picket line.

The other worker was a contractor.

Whether the workers' deaths will have an impact on negotiations between BART management and its unions remain to be seen.

Candlelight vigil

About 60 people, mostly BART employees, held candles in a circle during a vigil at the Walnut Creek BART station Sunday night. They offered condolences to the families of the two deceased workers, and repeatedly said the tragic accident was preventable.

Richard Stingily of Antioch, a 23-year BART employee, said, "Absolutely no one deserves to be killed in an accident like this. I can't imagine how the families are feeling. Make no mistake, safety issues and work rules are paramount."

BART spokeswoman Alicia Trost said in a statement issued Sunday afternoon that BART's board of directors will hold a special closed session meeting at 3 p.m. Monday, but that no talks between management and union leaders are scheduled.

The two sides have been in contact with one another, as well as with a mediator to determine what's next, Trost said.

"Since there is no announced end to the strike, commuters are urged to continue to make alternate plans," Trost said in the statement.

BART General Manager Grace Crunican would not comment on the labor issues in the aftermath of the deaths, nor would Amalgamated Transit Local Union 1555 president Antonette Bryant.

Union officials repeatedly warned the public during contentious negotiations that managers would create dangerous situations by operating trains, while management assured the public that those operators were certified and safe, and might shuttle a smaller fleet of trains if the strike lasts a long time.

Asked about the strike, Southworth said: "We are aware that there is a strike going on, but we don't know if or how it ties in. We are interested in everything."

Staff writers Matthias Gafni, Gary Peterson and Katie Nelson contributed to this story. Contact Rick Hurd at 925-945-4789 and follow him at Twitter.com/3rdERH.