The internal troubles of the D.C. Fire and Emergency Medical Services Department have long been an open secret in Washington: enormous overtime spending has been a persistent issue, labor and management appear to be in a perpetual state of war and staffing plans have led to public spats.

But the department's plights came into sharp focus last week when an injured D.C. police officer had to wait 18 minutes for an ambulance from Prince George's County because the city didn't have one available, an episode that's now the subject of a wide-ranging probe.

And on Thursday, firefighters had to transport a man suffering from a stroke to a hospital in a fire engine because -- again -- an ambulance couldn't reach him quickly enough.

The department's critics say last week highlighted their long-held concerns about the agency's future as the city's population grows.

"We're treading water," said Edward Smith, who leads the firefighters union. "You can still savage the department, but you have to do things smart."

And Ward 6 Councilman Tommy Wells, who took over as the chairman of the D.C. Council's public safety committee in January, said he had "already uncovered a number of issues that give me grave concern."

"There does seem to have been a history of breakdowns before Ellerbe, and now some of those are back," Wells said. "It's been a troubled agency for quite a while."

But top city officials contend the department, while imperfect, is still a high-performing agency that citizens can trust.

"Our department responded as best it could," said D.C. Fire Chief Kenneth Ellerbe in the aftermath of the week's episodes. "The citizens should have confidence because people have been transported, we are responding to emergencies as best we can and we have a plan to respond and do better."

Ellerbe acknowledged the department is at a crossroads.

"We know that we are at a tipping point in terms of providing services," he said, adding that he had proposed changes that had been rebuffed by labor unions.

Mayor Vincent Gray, who was adamant that Ellerbe retains his confidence, also acknowledged there was room for improvement.

"We want every one of our departments to run with 100 percent effectiveness," Gray said. "If there are issues that are raised, of course you want to find out and then get to the bottom of them and make sure they're fixed."

Smith said the city must act urgently or the problems that surfaced last week will only worsen.

"Summertime is just going to be bad. We have a higher demand for EMS in the summer, and there's more violent crime in the summer," Smith said. "We need a short-term plan that will maximize resources we already have but will not rob the residents of coverage, but we also need a long-term plan."

D.C. officials said they are committed to working with the union. Last week, at the height of the criticism of the department, Ellerbe and Smith sat down to talk about possible solutions.