The two-man team led by Jim Southworth, the board's railroad accident investigator-in-charge, will be looking at everything leading up to the collision, from safety procedures and qualifications of personnel to the track's condition.
"We will be the lead agency in the safety investigation into how and why this happened," Weiss said.
The four-car BART train with several people aboard was being run in automatic mode under computer control at the time of the accident, Assistant General Manager Paul Oversier said. The system has been shut down since Friday because of a work stoppage by the system's two largest unions.
The train was returning from a yard where workers cleaned graffiti from unused cars when it slammed into the two workers — one a BART employee and the other a contractor — who were inspecting an above-ground stretch of track between stations, Oversier said.
Neither BART nor the county coroner has released the names and ages of the victims. They were the sixth and seventh workers to die on the job in the system's 41-year history.