May 30 (UPI) — Bernard Kerik, New York City’s police commissioner on Sept.11, 2001, died Thursday at the age of 69.

Kerik was hailed as a hero for his response to the terror attacks on the World Trade Center and Pentagon, but fell from grace after pleading guilty to federal corruption charges and tax crimes in the years that followed.

F.B.I director Kash Patel said in a statement on social media Thursday night that Kerik had died “after a private battle with illness.”

“With over forty years of service in law enforcement and national security, he dedicated his life to protecting the American people,” Patel wrote.

Kerik rose to prominence as former New York City Mayor Rudolph Giuliani‘s bodyguard during Giuliani’s 1993 mayoral campaign. He worked his way through the ranks of the police department as a street cop and narcotics officer in some of the city’s busiest and most heavily trafficked areas, including Times Square, before being promoted to corrections commissioner where he took on the abuse of sick time by fellow officers and worked to reduce violence among prison inmates.

Kerik’s rapid rise through the ranks prompted criticism among many, who were quick to point out that he did not have a college degree or the necessary experience to carry out the duties of a high-ranking bureaucrat in the nation’s largest and most closely scrutinized police department.

Officers at Kerik’s rank were typically required to have a college degree, which he did go on to earn in 2002.

Crime declined during his tenure as police commissioner, but his critics said that was a continuation of the success that had been achieved by two of his predecessors.

Despite heavy criticism and scrutiny, Kerik received several meritorious awards, including the title of Commander of the British Empire, bestowed on him by Queen Elizabeth II.

In 2009, however, Kerik pleaded guilty to eight charges ranging from tax evasion to theft of honest services, making him the first city police commissioner to become a felon. He was sentenced to 48 months in prison.

The New York City Police Department issued a statement Thursday night saying it was in “mourning” over Kerik’s passing.

“For nearly two decades, Kerik served and protected New Yorkers in the NYPD, including helping rebuild the city in the aftermath of 9/11,” the police force said on X.

“We offer our deepest condolences to his family and loved ones.”

Andrew Giuliani, son of Rudolph Giuliani and a member of the Trump administration’s White House, said in a statement Thursday that “New York lost one of our greatest crime fighters this evening.”

“Bernard Kerik set the standard, turning the most dangerous Correctional systems in the world into the gold standard,” he said on X, adding that as police commissioner on Sept. 11, “Bernie led from the front.”

“Personally, I will always remember Bernie through the eyes of my seven-year-old self, as one of the toughest cops a boy could imagine.

“Rest in peace my friend; you rock; you great warrior!”