Metro knew for years that a federally funded alarm system that warns of out­ages in its emergency response radio network didn’t work properly in subway tunnels, but the agency never told the fire officials who depend on the equipment, senior emergency responders said.

When fire officials learned of the problem on their own last year and pressed Metro to fix it, the transit system said it was waiting until a new radio network is installed beginning a year from now.

Nonfunctioning radios complicated District firefighters’ rescue of Metro passengers who were trapped in a smoke-filled tunnel outside the L’Enfant Plaza station last month. One rider died, and scores of others suffering smoke inhalation were sent to hospitals

The Yellow Line accident on Jan. 12 is the latest example of the Washington region’s continuing struggles with emergency response, despite spending nearly $1 billion in federal homeland security grants since the Sept. 11, 2001, attacks in order to be nimble in a crisis.

Police, fire and other local agencies have enjoyed a flood of federal and local spending on security since the 9/11 assaults.

How the ventilation systems inside the tunnel affected the smoke.

They bought new equipment — including digital radios and antenna towers, surveillance cameras, high-tech command centers and suits of protective gear for firefighters. Large sums have also gone to fund planning and training exercises.

The Metro system alone has received $172 million from the Department of Homeland Security. The radio network inside Metro tunnels was built in part with $11 million of the grants.

But the L’Enfant Plaza incident exposed serious gaps in crisis reaction, some of which were similar to those in previous incidents. Local officials ranging from U.S. senators to county council members have raised questions about how well federal money has been spent.

The faulty alarm system appears to be one example of money that was wasted. Metro spokesman Dan Stessel said that a system was installed for about $2 million but that it did not produce reliable results and required extraordinary efforts to maintain.

As a result, Stessel said, Metro never advised the fire departments that the monitoring system had been activated in the first place.

He shifted the responsibility to the fire departments, saying that Metro’s “expectation was and is that the fire departments test radio coverage routinely.”

It’s not clear that the alarm system, had it been working, would have given Metro and firefighters earlier notice of the radio outage than they already had.

Christopher Hart, acting chairman of the National Transportation Safety Board, speaks to the media about the investigation into a fatal Jan. 12 incident on a Yellow Line Metro train that left one person dead and more than 80 others hospitalized. (Lori Aratani/The Washington Post)

But the fire officials said the alarms would have provided early alerts to Metro of many other outages found in the radio network. The episode was an example of what Prince George’s County Fire Chief Marc S. Bashoor, chairman of the region’s fire chiefs committee, called Metro’s record of “lack of transparent cooperation.”

Fire officials in the region said they were surprised and disappointed when they became aware last year that the alarm system wasn’t functioning. Regional fire documents show that alarms were purchased in 2006 and that in 2007, Metro was expected to start working to get the alarms functioning.

“To know that that system hasn’t been alarmed in years basically means we’ve been living on borrowed time,” said Montgomery County Fire Battalion Chief Michael Baltrotsky, a member of the region’s subcommittee on fire communications. “It’s scary to know that, and from a public safety standpoint, it’s simply unacceptable.”

The region’s challenges in emergency response arise not from a shortage of money or high-tech gear but from human, bureaucratic and training failures, according to local officials, industry experts, and current and former emergency responders.

In the Yellow Line accident, federal safety investigators cited Metro’s lack of written guidelines and proper training in concluding that the transit system mishandled ventilation fans that could have cleared smoke from the tunnel.

Separately, police radio trouble caused by too many users was reported in 2013 during the murderous rampage at the Washington Navy Yard. That same year, the inability of Capitol Police and the Secret Service to easily communicate might have hampered their response during the pursuit and fatal shooting of a driver turned away from a White House security gate.

“It’s not just a technology issue, it’s even more fundamentally a human institution issue,” said Falls Church Vice Mayor David F. Snyder, a longtime member of the region’s Emergency Preparedness Council. “Frankly, incident after incident shows there needs to be structural improvements.”

Many local leaders bristle at suggestions that the region is not well prepared to cope with a terrorist attack, natural disaster or similar tragedy. They stress that the Washington area, in many ways, is ahead of most other U.S. metropolitan regions.

For instance, D.C., county and other suburban firefighters and police in the region all use digital radios that are fully interoperable — meaning that a firefighter in Fairfax County can easily talk to one in Arlington or Montgomery counties.

But that advantage is partially undercut by the fact that many military and other federal agencies, as well as the Metro Transit Police Department, use different radio systems. Communication across agencies, therefore, requires extra equipment, time or attention that is not necessarily available in a crisis.

In the Metro incident, firefighters’ radios didn’t work because a network of antennas and amplifiers in the tunnel — the system that was supposed to have working alarms — wasn’t operating.

The network carries signals from tunnels and underground stations to key command personnel above ground. Instead, firefighters at L’Enfant Plaza had to use cellphones and a person-to-person relay system.

In a telling sign of the bureaucratic tension that afflicts the region, the first response from both Metro and the District was to blame the other.

District officials stressed that they had reported the radio outage at the L’Enfant Plaza Station to Metro four days before the accident but that Metro failed to make the fix. They learned of the outage not from the alarm system but when firefighters discovered that their radios didn’t work when they were called to the station for a debris fire.

Stessel said that the network was down on Jan. 12 because the District had failed to notify it of changes in electronic signal configurations affecting the system. He emphasized that the changes were made in equipment at an office on Fourth Street in Northwest, for which the District controls access.

The friction over alarms highlighted what the region’s fire chiefs complained was a past pattern of poor cooperation on Metro’s part that puts the public at risk.

The Yellow Line accident led the region’s fire chiefs to agree with Metro to test the radio system more frequently and to speed repairs.

In announcing that accord, Bashoor noted that Metro had turned more responsive since the Yellow Line accident.

“We are now getting the cooperation we need. There have been lapses in the past,” Bashoor said at a Feb. 11 hearing of the Metropolitan Washington Council of Governments.

Asked afterward to describe the earlier problems, Bashoor said: “Some of the lapses in the past have revolved around the lack of communications about the status of radio system repairs. They’ve also revolved around what we felt was a lack of urgency on WMATA’s side to get technicians out to the scene of a reported problem.”

Edward R. Mills III, a senior D.C. fire official, said at a congressional hearing that during radio testing the week of Jan. 19, nine facilities on four Metro lines failed inspection. All have been repaired, he said.

Fire officials learned that the alarms weren’t working when they asked Metro in October why the monitoring system hadn’t alerted them to outages they had discovered in other ways.

In an Oct. 27 e-mail, Metro communications official Matthew Lang confirmed that the alarm system wasn’t working. Fire officials said Metro tried to replace the original alarm network but the effort failed.

Since 9/11, Metro has been one of the region’s top recipients of homeland security grants. In addition to funding the tunnel radio network, the money has paid for 3,500 security cameras, an anti-terrorism team, operations control centers, and lighting, fencing and guard booths at Metro facilities.

The grants to Metro are part of more than $950 million that the region as a whole received from the Department of Homeland Security from 2002 to 2014, according to the D.C. Homeland Security and Emergency Management Agency.

That included $67 million spent on radio projects alone, according to the D.C. agency, which administers the money for the region.

One project begun too late to help during the Yellow Line accident is a revision and enhancement of plans for emergency response and evacuation at each of Metro’s 91 stations.

The effort, which began in 2012 with a federal grant, is adding such details as pre-established locations for command posts, staging areas for responders and locations for bus shuttles if needed.

Plans have been prepared for 25 stations. The one for L’Enfant Plaza is yet to be done.