Mayor Eric Adams and Fire Commissioner Laura Kavanagh made the announcement Friday, just four days after Firefighter Moon's tragic accident.
At around 12 p.m. on Dec. 12, Firefighter Moon was preparing for a drill in the firehouse, located on Sterling Place, and fell about 20 feet and suffered a serious head injury.
Moon was standing on an elevated platform as a drill simulating the rescue of trapped window washers when he suddenly fell from the makeshift scaffolding.
He was treated for his injuries by his fellow firefighters and was then rushed to Kings County Hospital in critical condition, officials said.
"This is a heartbreaking loss for New York's Bravest, and for our entire city," said New York City Mayor Eric Adams. "Firefighter Moon was a dedicated public servant, who spent more than two decades saving the lives of New Yorkers and will continue to do so in his passing. We join the entire Fire Department and every New Yorker in mourning his loss, and pray for Firefighter Moon, his family, and his friends."
His family has made the decision to donate his organs to save the lives of others. The family, his wife, Kristina, and their two children, live in Islip.
"Our hearts are broken for Firefighter Moon's family and friends, and for our entire Department. He spent his life helping others, here at the FDNY, and on Long Island, as a volunteer Fire Chief. Firefighting was in his bones, and he embodied the spirit and passion of our Department. He was passionate about organ donation, and just as he saved countless lives working out of the firehouse, he will continue to save lives in his passing," said Fire Commissioner Laura Kavanagh.
Kavanaugh also read words from Moon's wife:
"Loving Billy wasn't a just a marriage of families, his love and passion for the job extended far from the fire house walls, he instilled that same passion in our children and always talked about how important it was to help others."
Moon joined the FDNY in May 2002. He started his career in Queens, where he worked for 20 years before joining the Rescue Company 2 earlier this year.
The 47-year-old also served as a member of the Islip Volunteer Fire Department on Long Island and was the Chief of Department in 2017.
"This is a devastating tragedy that breaks the hearts of each and every member of the FDNY Firefighter family. Firefighter William P. Moon spent his life and career saving the lives of New Yorkers, and to learn of the donation of his organs, he will also do so in his passing. With more than two decades in the Department, Firefighter Moon was an exemplary member of the FDNY, whose contributions to his fellow firefighters, the Department, and this city will never be forgotten. The Uniformed Firefighters Association will stand 20,000 strong with the family of Firefighter Moon and honor his legacy of service and selfless sacrifice for the safety of others forever," the FDNY said in a statement.
One year ago this month, 31-year-old Vincent Malveaux, a probationary firefighter from Brooklyn, died a day after suffering a medical episode during academy training on Randall's Island.
And last February 33-year-old Firefighter Jesse Gerhard died after suffering a medical episode at a Queens firehouse after returning from battling a fire.
MORE NEWS: How to tell the difference between RSV, flu and COVID-19
RSV, flu and COVID-19: How can you tell the difference? Doctor explains
----------
* Get Eyewitness News Delivered
* Follow us on YouTube
* More local news
* Send us a news tip
* Download the abc7NY app for breaking news alerts