Metro on Saturday began to require its employees to trigger a full emergency response when a passenger train, bus or MetroAccess car breaks down in light of safety and reporting failures that officials said occurred last month, including an unreported runaway train.

The changes stem from a March 26 incident in which a Red Line train had a mechanical problem and stopped about 100 yards from the Rhode Island Avenue Metro station in Northeast Washington, stranding 109 passengers onboard. After more than an hour, riders were escorted off the train, and no one was seriously injured.

The missteps are the latest involving Metro’s Rail Operations Control Center, or ROCC, which has been under pressure to change its safety response, reporting practices and procedures since the Washington Metrorail Safety Commission issued a 50-page audit in September. That audit described the main control room for all Metrorail operations as a “toxic workplace” and cited 21 safety failures or workplace issues that it said put Metro passengers and workers at risk.

“As we reviewed these incidents, it became clear to me that additional steps are needed to achieve our organizational commitment to a ‘Safety Trumps Service’ operating ethos,” Metro General Manager Paul J. Wiedefeld said, referring to the latest incident in an internal memo Saturday obtained by The Washington Post. “Together, these actions move us another step forward toward strengthening a culture of safety within our operations.”

During the March incident, two people were treated at the scene for dehydration and anxiety. The breakdown’s cause is under investigation.

But it was in the response and reporting of the breakdown in which Metro made several missteps, Wiedefeld said. Customers sat onboard for 90 minutes without necessary guidance, he said. Two passengers evacuated the train, a dangerous move on busy tracks that include an electrified third rail that powers the system.

Police were called in to assist, Wiedefeld said.

“Communications between the ROCC and the field were inadequate regarding recovery efforts,” Wiedefeld said.

After passengers were safely offloaded from the train, Metro employees started preparing the disabled rail cars for a tow to Metro’s rail yard. At that point, the disabled train rolled 137 feet before a Metro worker could apply a hand brake to stop it.

Wiedefeld said the train moved at a speed of less than 5 mph and no one was hurt.

Workers on the scene did not report the rolling train to Metro’s ROCC and Safety department. He said internal safety inspectors “discovered” the event while listening to audio recordings of communications dispatches during a post-incident review.

But Max Smith, spokesman for the Washington Metrorail Safety Commission, an independent agency created by Congress to monitor Metrorail safety, said it was the commission’s inspectors who learned of the runaway train during their investigation, and they told Metro safety officials about it. They also first learned about the two passengers who had evacuated themselves, Smith said.

“The [safety commission] identified several issues in this event that were not initially identified by [Metro]," Smith said. “The [commission] has required full reporting and accurate reporting of the customer self-evacuation and the runaway train event.”

Smith said Metro also failed to notify the Federal Transit Administration of the runaway train, as federal regulations require.

Wiedefeld said that in the wake of the missteps, he is changing the way Metro responds to breakdowns of any passenger vehicles, including Metrorail, Metrobus and MetroAccess, which is Metro’s paratransit service for disabled customers.

Rail operations, he said, will develop instructions and retrain staff on how to attach rail cars properly. Metro’s Safety department and its Office of Emergency Management will have representatives in the ROCC “on a 24-7 basis to coordinate incident response.”

Metro employees will develop a playbook on how to assure and monitor passengers during service delays, breakdowns or disruptions. Safety officials will remind Metro staff of their duty to report “unusual occurrences, such as rolling events,” Wiedefeld said.

He said he also is lowering Metro’s threshold for what is considered an emergency. Any time a train, bus or MetroAccess car breaks down, he said, emergency management staff must be notified.

Many emergency functions not related to law enforcement or first responders will move out of the auspices of Metro Transit Police and under the umbrella of Metro’s Safety department to improve coordination.

“By Monday, all incidents of trains, buses and paratransit vehicles disabled for any reason and for any amount of time will qualify for a new, lower threshold for internal notifications of all departments,” Wiedefeld said. They include Metro’s Safety department, rail and bus operations, Metro’s Customer Service and Communication Marketing department and Metro Transit Police.

Wiedefeld said Metro’s chief safety officer, Theresa M. Impastato, will develop a plan to improve the transit agency’s entire emergency response program.

correction

A previous version of this article misstated the location of the Rhode Island Avenue Metro station. It is located in Northeast Washington, not Northwest.