National Transportation and Safety Board investigators work Jan. 12 in the tunnel near the site of a Metro incident near the L’Enfant Plaza station. (NTSB)

Members of the Washington area’s congressional delegation Tuesday urged Metro to “swiftly” rectify a safety flaw that was disclosed this week involving track-based power cables, saying “we are appalled that riders’ lives may have been put at risk” because some electrical connections in the subway are not fitted with proper protective sleeves.

The National Transportation Safety Board said it is trying to determine whether the problems contributed to the Jan. 12 incident in which an electrical meltdown involving track-based cables filled a Yellow Line tunnel with smoke, sickening scores of train passengers, one of whom died.

Saying they were “deeply disturbed” by an NTSB document that disclosed the problems Monday, the 13 members of Congress, in a letter, asked Metro to respond to Capitol Hill within 30 days, explaining how the agency plans to fix the shortcoming.

“This can’t be tied to a lack of resources,” Rep. Chris Van Hollen (D-Md.) said in an interview. “This is more a lack of sound management. It points to a dysfunction in the management system.”

Rep. Gerald E. Connolly (D-Va.) called the NTSB findings “really distressing.”

Metro jumper cables

“At this late stage, it’s hard to believe we’re still dealing with something like this, and it requires the NTSB to point it out,” Connolly said. “[Metro’s] own internal systems didn’t uncover this. And that erodes confidence, even among red-blooded supporters like myself. There has to be a significant shake-up to respond to these challenges.”

“We absolutely understand the delegation’s concerns,” Metro spokesman Dan Stessel said. He said Metro’s deputy general manager, Rob Troup, will give a “full public briefing” on the situation at Thursday’s meeting of Metro’s board.

The transit agency, contrary to its engineering guidelines, failed to install the proper kind of weather-resistant “sealing sleeves” over power-cable connections in a number of places throughout the subway, according to the NTSB. The board said it also found that some cable-connector assemblies were improperly constructed.

The poor construction and absence of proper sleeves “can lead to short circuits that can generate fire and smoke in tunnels” the NTSB told Metro in the 10-page document .

In the Jan. 12 incident, in the Yellow Line tunnel just south of the L’Enfant Plaza station, electricity escaped from power cables and generated tremendous heat and smoke, the NTSB said. The board said that damage in the tunnel was so severe that investigators so far have been unable to determine if cable connections there were properly constructed and fitted with the right kind of protective sleeves.

However, the NTSB said, “even the post-accident repairs made to the power-cable connector assembly at L’Enfant Plaza did not include the sealing sleeves indicated in the WMATA engineering design specifications.”

Investigators found a similar problems at “a number” of locations in the subway, including near the Court House station in Virginia after a smoke incident there in February. The NTSB urged Metro to immediately begin fixing the problems, saying, “We are vitally interested in this recommendation because it is designed to prevent accidents and save lives.”

The findings riled the area’s congressional delegation.

“We are appalled . . . because a small, yet critical component of the power cables was not installed as required by the manufacturer's directions and [Washington Metropolitan Area Transit Authority] engineering specifications,” the delegation said in its letter Tuesday to interim Metro General Manager Jack Requa.

“Problems arising from aging infrastructure may be understandable, but WMATA must explain how failure to follow basic assembly instructions has been allowed to persist,” the letter said. The delegation said it wants “a system-wide accounting of power cable connector assemblies that do not include sealing sleeves or other proper components.”

In its document to Metro, the NTSB said heat from electricity that was escaping from cables in the L’Enfant Plaza tunnel caused “extensive thermal damage,” which “consumed evidence in the area of the short circuit.”

“The investigation is ongoing and additional analysis is needed before the cause can be determined,” the safety board said. “However, the investigation of this accident and evidence from another recent WMATA incident,” the one near Court House, “indicate a safety issue concerning improperly constructed power-cable connector assemblies.”

The NTSB, which will hold public hearings on the L’Enfant Plaza incident June 23 and 24, has said its final report probably will not be done until early next year.