 The 1000 @-@ Series entered service in 1976 when the Metro system opened , and were refurbished and had their motors converted from DC to AC propulsion by Breda Costruzioni <unk> in the mid @-@ 1990s . In 2006 , the NTSB cited the 1000 @-@ Series cars as " vulnerable to catastrophic telescoping damage and complete loss of occupant survival space in a longitudinal end @-@ structure collision " . It recommended refurbishment of the entire series after a 2004 collision at the Woodley Park station in which a 1000 @-@ Series Rohr car telescoped into another train . In this case , NTSB 's Hersman confirmed that , " the first car [ of the striking train ] overrode the rear car [ of the struck train ] , and much of the survivable space on that first car of the striking train was compromised " . The NTSB called for the accelerated retirement of the 1000 @-@ Series cars , or urged that they be " retrofitted with <unk> collision protection that is comparable to 6000 @-@ Series car railcars . " Additionally , the 1000 @-@ Series cars lack data recorders that could be used in determining the cause of a crash . During the press conference , Catoe stated that he had " no basis to suspend the use of 1000 @-@ Series cars at this time " . However , WMATA later announced a decision to no longer use the 1000 @-@ Series cars as the lead or trailing units of any trains . 
