Three-term Brockton Mayor Bill Carpenter, who was called a "deeply committed public servant," died unexpectedly Wednesday.
The 62-year-old was found unresponsive in a car parked at a city school, authorities said.
Carpenter was discovered by police responding to an emergency call around 7:30 a.m. at the Arnone School, where he had gone to drop off a family member at a summer program, according to a statement from Plymouth District Attorney Tim Cruz.
Carpenter was taken to a hospital where he was pronounced dead. Cause of death was not immediately known, but Cruz said no foul play was suspected.
The Enterprise of Brockton reported in March that Carpenter underwent a procedure for a cardiac artery blockage after experiencing chest pain and shortness of breath. He returned to work within about a week and was planning to seek another two-year term in November.
"Our hearts go out to the family of Brockton Mayor Bill Carpenter, a deeply committed public servant who was dedicated to improving the lives of his neighbors," Gov. Charlie Baker said on Twitter. "We join them and the entire community in mourning his passing."
Carpenter, an independent, was first elected mayor in 2013 after serving on the school committee.
A city of nearly 100,000 residents in southeastern Massachusetts, Brockton is nicknamed "city of champions" for being the hometown of former world boxing champs Rocky Marciano and "Marvelous" Marvin Hagler.
Carpenter had a prominent link to the boxing world himself, having previously been a professional boxing ring announcer, according to a biography on the city's website, which said he also served for 17 years as the radio broadcaster for Brockton High School sports.
As mayor, Carpenter won praise for his work in dealing with the opioid crisis. He was the only mayor named by Baker in 2015 to the Governor's Opioid Addiction Working Group. In 2016, he launched "The Champion Plan," a program aimed at getting residents with substance abuse disorders into addiction treatment.
Cruz lauded Carpenter for working with the district attorney's office to make the city safer.
"A long time participant and attendee at our Operation Safe Streets community meetings, he ensured the participation and cooperation of all levels of city government, from the police to city hall, in our collaborative efforts to make the city a safer place for everyone who lives and works here," said Cruz.
Carpenter was the father of six children, one of whom is a city police officer, the Enterprise reported.
His death prompted an series of social media tributes from state and municipal officials.
"It is a sad day in Brockton and across the Commonwealth, created by the passing today of our City's three term Mayor, Bill Carpenter," Brockton Rep. Michelle DuBois posted on Facebook. "RIP Mayor Carpenter. My condolences to Mayor Carpenter’s family, his partner Julie and all who knew and loved Bill."
Lt. Gov. Karyn Polito tweeted that Carpenter was "a relentless force behind the progress being made in the City of Champions."
Attorney General Maura Healey called him "a true ally in fighting the opioid crisis."
Gloucester Mayor Sefatia Romeo Theken said she was "devastated" to learn the news and sent condolences from her city to Brockton. "He was a wonderful man, kind, funny, friendly," she wrote.
Information from the WBUR newsroom was used in this report.