PHILADELPHIA (CBS)—The Philadelphia Fire Department is mourning the loss of one of their own.

According to the fire department, Lt. Kenneth Greene Sr. died on Thursday after he was transported to the hospital while on duty on Sept. 3.

Greene, 60, was a veteran of the United States Army, and served on the city fire department for 23 years.

In 2007, his unit at Ladder 14 received a citation for helping to rescue two people from a house fire in Brewerytown.

Circumstances surrounding Greene’s death has not yet been released.