Metro’s admission this week that it failed for a month to properly fix a major track defect that caused a derailment after it was detected is the latest example of the transit agency’s mishandling the repair of a known safety risk.

After a fatal smoke incident Jan. 12, federal safety teams urged Metro to install proper protective sleeves over power cables in a number of places throughout the rail system to reduce smoke and fire hazards. Metro failed to follow its own guidelines and did some of the repairs incorrectly, the National Transportation Safety Board determined in June.

Also, the NTSB found that exhaust fans that could have helped clear smoke during the Jan. 12 incident had not been routinely tested according to Metro’s own procedures, even though transit agency maintenance records showed that the tests had been done. Two fans failed to work when noxious fumes enveloped a train stalled in a smoke-filled tunnel. One passenger died, and scores were sickened.

On Wednesday, Metro acknowledged that routine testing in early July uncovered a track flaw significant enough that it should have triggered an immediate shutdown of that section of rail. The repair wasn’t made, and a train preparing for morning service on Aug. 6 derailed at the same spot when the wheels of three cars slipped off the track between the Smithsonian and Federal Triangle Metro stations.

Wednesday’s revelations led even some of Metro’s fiercest supporters to call for faster and more public answers about why the transit agency is not following its own procedures.

The calls included some from quarters that previously have shown patience and even sympathy when Metro said it has been hobbled by financial pressures and years of deferred maintenance.

The latest incident also comes as Metro already is under increased scrutiny from a number of federal agencies for its safety lapses, management problems and financial woes.

On Thursday, Metro’s board demanded that the interim general manager, Jack Requa, finish an investigation into the mishandling of the track defect within 10 days and “explain to the Board and our riders how this track deficiency went unrepaired for so long.”

Calling it an “unforgivable breach of safety” to take a month to repair the defect, the Metro board said in a statement that it “is outraged and dismayed that anyone working at Metro would have critical safety information and not act on it immediately.”

“This is a breakdown of the organization’s chain of command and our safety culture,” said board member Michael Goldman, who chairs the panel’s safety committee.

Metro's interim general manager, Jack Requa, says that the track defect that caused a Metro derailment was detected in July but had not been fixed. (WUSA9)

“This should have gotten top priority. Why it didn’t is very troubling. If it’s the system, the people or a combination of both, we need to find out,” Goldman said.

Citing an ongoing internal investigation, a Metro spokesman said transit agency executives would not be available to discuss what they might already know about the specific lapses preceding last week’s derailment. Nor would they be interviewed about the general process for checking tracks for defects, prioritizing trouble spots for attention and then relaying those work orders to maintenance crews.

“The ongoing investigation is focused on determining who knew of the defect and where the breakdown occurred” before the derailment, Metro spokesman Dan Stessel said in an e-mail.

But at the Federal Transit Administration, Therese McMillan, the acting administrator, pointed to a pattern of broad safety management deficiencies.

Based on Requa’s explanation, McMillan said in a statement, “the Aug. 6 derailment incident is another example of a failure by Metrorail to effectively execute its own safety programs and system maintenance.”

The defect found in the track July 9 merited a “black” designation, which should have shut down a section of the rail, Rob Troup, Metro’s deputy general manager, said Wednesday.

Whether it was flagged that way and overlooked or wasn’t recognized as urgent is one of the questions Metro has not answered yet.

Inspectors assign colors to designate track conditions: green, which means no restriction; yellow to red, which imposes speed constraints; and black, which is an immediate shutdown, Stessel said.

The “wide gauge” flaw — which causes a train’s wheels to lose contact with the rails — emerged Aug. 7 as a possible cause of the derailment and was confirmed Wednesday, Stessel said.

At the same time that Requa conceded the month-long lag between the defect’s detection and repair, he said Metro had begun emergency inspections of the system’s 234 miles of track that day, a process that could take up to four weeks to finish.

The derailment also focused the criticism coming from the Tri-State Oversight Committee, the regional safety oversight body for Metro.

“TOC is gravely concerned at WMATA’s failure to address a major track defect in a timely manner,” the panel said in a statement.

Requa said that Metro is investigating the derailment following FTA regulations and in cooperation with the TOC. By e-mail, Requa said he expects a draft report in about 30 days. That doesn’t preclude further public statements about the incident before then, Stessel said.

Metro uses walking inspections as well as a special train car to check track conditions and standards.

The special vehicle is designed to give workers an instant readout of track anomalies so workers can quickly identify and flag problems. As the vehicle travels along the track, it alerts workers to anomalies as they were discovered, according to a person who is familiar with how it operates. What is unknown is what happened to the information that detected the problem that caused the derailment.

At the end of the vehicle’s tracking session, workers receive a full readout that would flag defects and their severity, said the person, who spoke on the condition of anonymity because of a lack of authorization to speak publicly about it.

“You didn’t have to wait,” the person said. “You had the information right away.”