A Philadelphia police lieutenant has died from the coronavirus, the Montgomery County Coroner’s Office said Monday — the city’s first employee to die as a result of the pandemic.

Lt. James Walker, 59, was pronounced dead Sunday at Abington Hospital-Jefferson Health, the Coroner’s Office said. A 32-year veteran of the department, Walker had been assigned to the traffic division. He previously worked in eight different police districts as well as in Internal Affairs and on the Narcotics Strike Force, the Police Department said.

Word of Walker’s death came as law enforcement sources told The Inquirer on Monday night that 52 city police officers had tested positive and dozens more were self-quarantining, either because they are symptomatic and awaiting test results, or because they had been exposed to others who have tested positive.

Walker’s wife, Vita, said Monday that Walker was admitted to the hospital on March 27 for symptoms including difficulty breathing, and that his positive test result for the coronavirus came back the next day.

He remained hospitalized as his health declined in the days that followed, she said, and was eventually placed on a ventilator. She was unable to see him because she is asymptomatic, but said a nurse was with him when he died.

Vita Walker described her husband of 36 years as dedicated to his family and the Police Department, a no-nonsense and straightforward man with a “bigger-than-life personality.”

“He was a good man,” Vita Walker said. “He was a man among men.”

Mayor Jim Kenney said Monday that officials were not certain how or where Walker might have contracted the virus.

Police Commissioner Danielle Outlaw said in a statement that Walker’s death was “deeply painful," adding: “The loss of his life illustrates the commitment that he and members of the Philadelphia Police Department have to serve the communities of this city, even in times of unprecedented risk and challenge.”

John McNesby, president of Fraternal Order of Police Lodge 5, said in a statement late Sunday: “We should never forget the sacrifices of our officers and those on the front lines battling this pandemic and working tirelessly to keep our great city safe.”

Tributes to Walker began pouring in on social media, with friends describing his death as heartbreaking and surreal. Inspector Verdell Johnson wrote on Twitter on Monday that Walker’s death was “another devastating blow to the Police Department.”

Walker’s death came weeks after Sgt. James O’Connor IV was fatally shot in Frankford while seeking to arrest a murder suspect. The city has been unable to hold traditional funeral services for O’Connor due to restrictions on large gatherings amid the pandemic.

It also came as law enforcement agencies across the country grapple with how to serve their communities while continuing to protect officers’ health.

Two Pennsylvania state troopers have tested positive for the coronavirus, said State Police spokesperson Ryan Tarkowski, and three troopers who had close contact with them are self-quarantining as a precaution.

The national Fraternal Order of Police said Sunday night that at least 21 officers across the country have died from the virus. And in cities such as Detroit and New York, hundreds of officers have called out sick or remain under quarantine.

Nearly 20% of New York’s Police Department called out sick on Sunday, according to the Staten Island Advance, and more than 2,000 NYPD employees have tested positive for the virus.

Philadelphia officials have declined to confirm how many police officers have tested positive for the virus. Managing Director Brian Abernathy said Monday that he did not see a benefit to making that information public.

Abernathy said the city was not seeing unusual absences among police officers and that "we’re a long, long way away” from needing to enact contingency staffing plans.

Last month, Outlaw announced a new policy instructing officers to delay arrests for most nonviolent crimes and instead issue warrants for suspects to turn themselves in after the pandemic subsides. The decision, which was made in part to try to protect officers’ health, was praised by advocates, the police union, and District Attorney Larry Krasner.

Vita Walker said she’d spent nearly every day with her husband over the last 36 years, and that being apart from him while he was sick was “unbearable.”

She said Walker is also survived by two daughters, Qiana and Khalia, and that funeral arrangements were pending.

Staff writers Mike Newall and Chris Williams contributed to this article.