Federal safety investigators plan to unveil on Tuesday what caused the deadliest crash in Metro's history, more than 13 months after nine people were killed and dozens more injured when a Red Line train slammed into a stopped train.

The National Transportation Safety Board has already indicated that problems with Metro's track circuit equipment contributed to the crash outside of the Fort Totten rail station, preventing the automatic safety system from stopping the trains before they got too close.

Possible NTSB targets »  Rohr 1000 series rail cars: Observers expect the National Transportation Safety Board to once again point to the rail cars as it has done repeatedly over the years, urging Metro to remove them from service because it says they aren't crashworthy. One of the rail cars crumpled to a third of its size in the deadly June 22, 2009, crash. Other cars from the 1000 series were seriously damaged in a West Falls Church rail-yard crash in November. Metro has pledged to replace its oldest cars, but its $886 million deal with Kawasaki Rail Car Inc. is on hold while the agency tries to untangle a snag with the federal "Buy America" requirement. Still, the replacement cars would not all arrive until at least 2016. Metro has said it cannot get rid of the cars in the meantime as they represent a quarter of its fleet. »  Mixed equipment: The NTSB will likely also provide clarity on a dispute between Metro and the track equipment manufacturers as to whether mixing different brands of equipment caused the track circuits to fail. Such direction could pave the way for establishing legal liability in a slew of lawsuits already pending from victims' families. -- Kytja Weir


Multiday investigative hearings in February also highlighted the flawed safety culture at Metro and the broader lack of oversight for transit systems nationwide.

The findings of the NTSB's lengthy investigation have been closely held. But the agency is expected to name the probable cause of the crash, plus make recommendations to the transit agency, the equipment manufacturers and other entities on how to prevent such tragedies from happening again.

"We're looking forward to seeing what the NTSB has to say," said Matt Bassett, chairman of the Tri-State Oversight Committee that is charged with monitoring Metro's safety.

But Kenneth Hawkins, who lost his brother Dennis in the crash, isn't getting his hopes up for any real changes. "I'm a little skeptical it is another thousand pages of paper filed in the record," Hawkins said.

He said Metro did not follow through with recommendations the NTSB made after a 2004 crash and he hasn't seen major changes at Metro yet. "All I've heard over the last 13 months is 'This is what we're going to do.'"

Metro spokesman Steven Taubenkibel said the agency has made dozens of safety improvements including implementing some NTSB recommendations in advance of Tuesday's hearing. "We stand ready to work with the NTSB to build upon our progress to date," he said.

The agency has set aside $30 million over the next three years to help pay for any NTSB recommendations. The Federal Transit Administration has also warned the agency that $150 million in federal funding may need to be reallocated depending on the recommendations.