Family, friends and colleagues of New Jersey State Police Lt. Bill Fearon are mourning his death from a 9/11-related illness.

Lt. Fearon was diagnosed last May with a malignant brain tumor. Officials say he was sickened during his work at Ground Zero after the Sept. 11 attacks.

Those closest to Lt. Fearon described him as strong-willed, a pillar in his community and selfless in his actions.

"He wouldn't have changed a thing. If you told him that things were going to be bad and he knew he could help, he'd still go and do it," says Sgt. Neal Picillo.

Lt. Fearon's neighbors say that even while he was battling his own sickness he continuously put himself before others.

"As Bill was going through this last year and a half, my wife was going through her own battle with cancer, and Janice [Fearon's wife] and Bill supported us," says neighbor Nick Nesto.

Friends say Lt. Fearon's efforts to inspire others was endless. Earlier in the year, he dressed up as Batman along with other troopers and talked to kids at the children's cancer center in Hackensack about his battle with the disease. He also gave them wristbands with the words "No Fear," a mantra he lived by.

Lt. Fearon told News 12 New Jersey at the time, "I just wanted the kids to have a good time and realize basically that things are never gonna be bad. Things aren't gonna be that bad all the time, and we always want to win."

Gov. Chris Christie has ordered flags to be lowered to half-staff on Saturday in honor of the lieutenant.

Lt. Fearon's wake is scheduled for Friday, with a funeral to be held on Saturday.