Firefighters load a victim into a medical bus after passengers on the Washington METRO (subway) service after smoke filled the L'Enfant Plaza station. (Paul J. Richards/AFP/Getty Images)

D.C. Mayor Muriel E. Bowser’s administration announced Wednesday that the District will abandon its new system of encrypting radio communications among firefighters and paramedics.

The District’s encryption came under intense scrutiny last month when Metro officials said they found changes to firefighter radio settings related to encryption following a widespread radio failure during Metro’s fatal Jan. 12 smoke incident.

In that incident, D.C. firefighters could not communicate with supervisors above ground when they learned that a train was trapped in a smoke-filled tunnel south of the L’Enfant Plaza station with more than 200 passengers aboard.

D.C. firefighters and the city’s homeland security agency have disputed that encryption played any part in the radio failure.

In a statement on Wednesday, Rashad Young, Bowser’s city administrator, said the encryption issue had been under review since before Bowser was inaugurated Jan. 2. Going forward, he said, encryption would be only used on a case-by-case basis.

“After a thorough review that began in December, Mayor Bowser has decided that it is in the best interest of the District and its residents to change encryption protocols,” Young said.

Two administration officials who spoke to the Post about the upcoming change on Tuesday stressed that the move was not an acknowledgment that encryption hampered rescue efforts last month, when Metro passengers waited for more than 35 minutes for help.

“It has nothing to do with the Metro incident,” said one of the two officials. Both spoke on the condition of anonymity because they did not want to be seen as preempting Bowser’s announcement. The impending announcement was first reported by WRC (Channel 4).

“The timing of the announcement has in fact been complicated because we don’t want to suggest in any way that it is connected to the outstanding allegation that [encryption and the Metro incident] are connected,” the official said.

The District began work to encrypt its radio transmissions after the 2013 rampage at the Navy Yard. The shooting that left 12 dead prompted a dangerous search by police as they hunted the gunman before fatally shooting him. Although communication involving federal and local police agencies could not be heard by outsiders, the fire department scanner — widely available over the Internet — provided an account of some of the behind-the-scenes activities. Firefighters were not in the building when the manhunt was underway.

Former mayor Vincent C. Gray cast encryption as important to keep real-time information away from criminals who might use it to further their purposes­ as well as to protect patient safety, because paramedics transmit information over radios.

But the District’s move to encryption drew rebukes last year from fire chiefs in neighboring jurisdictions in Maryland and Virginia who warned that it might complicate calls for mutual aid.

In a D.C. Council hearing last week on the troubled Metro response, Edward C. Smith, president of the D.C. firefighters union, renewed the union’s call for the District to reevaluate the utility of the system.Smith said that in rare circumstances encryption could be useful but that it should not be the norm.

Late Tuesday, Smith said, “We commend the Bowser administration for reversing a bad decision that was made by the prior administration.”

Asked about the change, Metro spokesman Dan Stessel said the transit agency did “not have a position on it one way or the other.”

“It is the District’s decision to make,” Stessel said. “What is important to us is that we are formally notified in advance anytime changes are made to a radio system that could affect its operation, and that those changes are followed by appropriate testing.”

Metro has asserted that the firefighters’ radio problems originated in a room that the District owns, operates and maintains that hands off radio transmissions from Metro tunnels to the D.C. system. When Metro and District radio technicians met after the incident, Metro said its workers found changes related to encryption and channel designations that were previously unknown to Metro.”

The District and Metro have since collaborated on weekly testing of all Metro stations and tunnels to make sure signals are working consistently.

On Wednesday, Metro and area fire departments were scheduled to begin discussions on formalizing a process to better coordinate on radio communications and to rapidly respond when failures are discovered.

D.C. firefighters’ radios failed five days prior to last month’s Metro incident, and in th same location, but remained inoperable on the day that a Virginia woman died and 80 others were hospitalized.

One of the administration officials said the District remains confident that the National Transportation Safety Board wouldn’t find fault with the city’s radio encryption in its review of the response to the Metro accident.

In his statement, Young said the new protocols would ensure that first responders from D.C. Fire and Emergency Medical Services can “seamlessly communicate with their counterpart agencies from other jurisdictions while embracing encryption technology that will ensure the safety and security of residents and visitors during incidents deemed sensitive.”

Peter Hermann contributed to this report.