The medical director of the District of Columbia’s fire department resigned Tuesday, but not before taking the opportunity to rip the mayor in a scathing letter that calls into question her ability to properly reform one of the nation’s worst emergency response time.

“People are dying needlessly because we are moving too slow,” Dr. Jullette Saussy said in a letter, which was shared with the Associated Press.

The fire department in the nation’s capital has a poor reputation for providing timely emergency care. Saussy said in the letter that a man died of a stab wound that he could’ve survived if he hadn’t waited 18 minutes for an ambulance.

The Associated Press reported in 2013 that the department was trying to make do with less than half the paramedics employed by departments with similar call volumes. The city has also struggled to dispatch calls in a timely matter.

Last year’s incident on the DC Metro – which killed one passenger when smoke filled a subway train – it took five minutes for the first firefighters to be dispatched to the scene. Also, a 1-year-old died after choking on a grape when the nearest ambulance wasn’t sent to the scene.

The death of the 35-year-old man who was stabbed last month was just one of many that have not been scrutinized by the public, Saussy said in her letter, dated Jan. 29.

"Tragically, people die needlessly quite frequently, and the majority of them don't make the news," she said.

Saussy submitted her resignation after less than seven months on the job, saying her efforts to reform the department had been stymied. She said the department’s culture “is highly toxic to the delivery of any semblance of quality pre-hospital care.”

Mayor Muriel Bowser has recognized the need for change. But Michael Czin, a Bowser spokesman, told the Associated Press that Saussy’s claims were largely inaccurate.

Bowser hired Gregory Dean as chief. Dean spent 10 years as chief of Seattle's fire department, which is recognized as a national leader in emergency medical care.

The Washington Post noted that Dean has major support in Seattle from the firefighters union and has escaped criticism when firefighters were dispatched to a call for a man dying of a heart attack but went to the wrong address.

The mayor pushed through a proposal to supplement the city's overworked ambulance fleet with private ambulances to handle low-priority calls. Saussy said that plan "is as unlikely to fix the situation as placing a Band-Aid on a gushing artery."

But administration officials say the private ambulances are just part of a multipronged approach to reforming the department, including better training for firefighters to handle medical emergencies.

The Associated Press contributed to this report.