In the 22 years that have passed since Sept. 11, 2001, just as many New York Fire Department employees have died from World Trade Center-related illnesses as died on the day at ground zero, the department says.

Over the weekend, the FDNY announced the deaths of EMT Hilda Vannata and retired firefighter Robert Fulco, bringing the total number of deaths from World Trade Center-related illnesses to 343.

The deaths of Fulco and Vannta mark a "somber, remarkable milestone," said FDNY Commissioner Laura Kavanagh in a statement Saturday.

"We have long known this day was coming, yet its reality is astounding just the same," Kavanagh said. "Our hearts break for the families of these members, and all who loved them."

According to the FDNY, Vannata died of cancer and Fulco of pulmonary fibrosis, a lung condition that can be caused by exposure to asbestos and other toxic materials. Both deaths were "a result of the time they spent working in the rescue and recovery at the World Trade Center site," the department said.

On Sept. 11, firefighters and paramedics raced to the World Trade Center, where fires raged after the twin towers were struck by terrorist-hijacked airliners.

More than 1,000 FDNY employees were on the scene when the towers collapsed. In total, 343 FDNY responders were killed that day.

After the attacks, the fire department continued to work at ground zero as part of a months-long recovery operation. Thousands of responders were exposed to dust that contained hazardous and toxic chemicals.

About 11,000 current and former fire department employees suffer from World Trade Center-related illnesses, including some 3,500 with cancer, the FDNY says.

A study published in 2019 found elevated risks of certain cancers among World Trade Center responders, including prostate cancer, thyroid cancer and leukemia. There is also some evidence that 9/11 responders are more likely to survive their cancer than the general population.

In total, nearly 80,000 people have physical or mental health conditions stemming from exposure to 9/11-related conditions, according to the Centers for Disease Control and Prevention.

One legacy of the attacks is a greater understanding of the risks undertaken by first responders at events of all kinds, said Lisa Delaney, associate director of emergency preparedness at the CDC, speaking to NPR earlier this month at the opening of an exhibit at the CDC Museum in Atlanta about the health effects of 9/11.

"It's always with us when we think about new emergencies — for example, the Maui wildfires — and now understanding what they were potentially exposed to and how that might impact their long term health," Delaney said.