More FDNY members have died from World Trade Center illnesses than killed on 9/11

Wednesday marks 23 years since the Sept. 11 terrorist attacks.

On the day the Twin Towers fell, 343 members of the FDNY were killed, according to officials.

In the 23 years since, more than 360 FDNY members have died of World Trade Center-related illnesses, the department said. Twenty-eight of those FDNY deaths were over the last year, according to the FDNY Uniformed Firefighters Association.

"Those insurmountable losses did not end at the World Trade Center site," New York City Fire Commissioner Robert Tucker said. "Instead, we have seen our members become sick because of time they spent working in the rescue and recovery."

Of the 2,753 people killed at the World Trade Center, about 40% -- 1,103 people -- remain formally unidentified. There has not been a new identification of remains since January.

The National September 11 Memorial & Museum's annual commemoration ceremony will take place on Wednesday, beginning at 8:30 a.m. ET.