NEW YORK (AP) — Officer Didarul Islam had a way of explaining policing as “a blanket of the community, there to provide comfort and care,” the head of the New York Police Department said Thursday.

“He made that his personal responsibility,” Police Commissioner Jessica Tisch said as family, friends, dignitaries and throngs of fellow officers paid tribute to Islam, who was among the four people killed in Monday’s attack at the midtown Manhattan office tower that houses the National Football League’s headquarters.

With officers stationed around the Bronx mosque for security on rooftops, fire trucks used their ladders to hold a huge American flag over a nearby street ahead of the service A flatbed truck carried a digital billboard showing photos of Islam and a commemorative message from his union. Officers lined up four deep outside.

Islam, 36, was working a department-approved private security detail, in uniform, when he was fatally shot in the attack. A security guard, real estate company employee and investment firm executive were also killed. The gunman also wounded a fifth victim, an NFL employee, before killing himself.

“This officer saved lives. He was out front. Others may be alive today because he was the barrier,” Gov. Kathy Hochul told mourners at the Parkchester Jame Masjid mosque.

An immigrant from Bangladesh, Islam was building a career in the nation’s largest police force. He served as a school safety agent before becoming a patrol officer less than four years ago, and was promoted posthumously Thursday to detective.

“He could have gone into any other occupation he wanted, but he wanted to put on that uniform, and he wanted to protect fellow New Yorkers. And he wanted to let us know that he believed in what this city and what this country stood for,” Mayor Eric Adams told the gathering. “That’s the greatest symbol of what we know we are as a country.”

“As the mayor of the city of New York, yes, I’m angry” about Islam’s death, Adams said. But he added: “I’m filled with hope and optimism today became of the life of Officer Islam.”

Islam was assigned to a precinct in the Bronx, the borough where he lived with his wife and two young sons. His widow is expecting the birth of their third child soon.

“To our family, he was our world. To the city, he was a proud NYPD officer who served with compassion and integrity. He lived to help others,” his widow said in a statement that a friend read on her behalf at the serve.

Islam will be buried later Thursday at a cemetery in Totowa, New Jersey.

Another victim, Julia Hyman, was buried following an emotional service Wednesday at a Manhattan synagogue. The 27-year-old Cornell University graduate had worked for Rudin Management, which owns the building.

Funeral arrangements for the two others killed, security guard Aland Etienne and investment firm executive Wesley LePatner, have not been made public.

Police identified the gunman as Shane Tamura, a 27-year old former high school football player who most recently worked in a Las Vegas casino’s surveillance department. Authorities say he drove to Manhattan because he believed he had a brain disease linked to contact sports and accused the NFL of hiding the dangers of playing football.

Officials said he was heading for the NFL’s office but took the wrong elevator and went by mistake to another floor that housed Rudin Management’s offices. The wounded NFL employee happened to be in the lobby when Tamura was firing there.

Adams, a retired police captain, said the bloodshed “cut me to my core.”

“For someone to drive across our country, carrying an automatic weapon and taking the lives of innocent people — we ask ourselves over and over again, ‘What more could we have done?’” he wondered aloud at Islam’s service.

Police said Tamura had a history of mental illness, but they haven’t elaborated other than to say they found psychiatric medication prescribed to him at his residence in Las Vegas.

___

Associated Press reporter Jennifer Peltz contributed.