Setti Warren, mayor of Newton from 2010 to 2018, has died at age 55.

Mayor Ruthanne Fuller wrote in an email to the community that she was shocked to hear of Warren’s death.

“Setti loved Newton, the community where he grew up, and combined that love with a passion for public service and an unshakeable belief that government can be a force for good,” Fuller wrote.

There was no cause of death announced as of Sunday night, and memorial service details have yet to be announced.

“On behalf of the residents of Newton, I extend our sympathy to his wife Tassy, his children Abigail and John, his extended family and many friends—as well as from me and my husband Joe, our love,” Fuller’s message concluded.

Warren had been serving as director of Harvard’s Institute of Politics since 2022.

Harvard Kennedy School Dean Jeremy M. Weinstein and Harvard College Dean David J. Deming announced Warren’s death on Sunday afternoon.

“He will be remembered at Harvard by the many students he helped to teach, nurture, and mentor,” the announcement read in part. “Setti’s students loved him, and their impact–like his–will reverberate for generations to come.”

U.S. Rep. Jake Auchincloss took to social media Sunday to express his grief for a friend an “an exemplar to everyone of public service.”

“When I first ran for City Council, it was his style of door-to-door dynamism that inspired me,” Auchincloss wrote.

Warren was born in 1970—along with twin sister Makeda—and raised in Newton in a family focused on social justice. His father, Joseph Warren, was an African-American studies professor who worked for the presidential campaign of Massachusetts Gov. Michael Dukakis in 1988. His mother, Elidia, was a social worker.

He had a younger sister, Kara, who lived with severe asthma and died at the age of 27 in 2005.

Warren went to Jackson Walnut Park School in Newton and later graduated from Newton North High School  where he served as class president. He was also student body president at Boston College, where he earned a degree in history in 1993, and got his law degree at Suffolk University Law School in 2006.

Warren worked for President Bill Clinton’s re-election campaign in 1996 and held various jobs in the Clinton administration from 1996 to 2001, including the role of regional director of the Federal Emergency Management Agency. He worked for the presidential campaign of U.S. Sen. John Kerry in 2004 and later worked in Kerry’s Senate office. Locally, Warren served on the Newton Community Preservation Committee and the Newton Economic Development Commission.

Kerry and his wife, Teresa Heinz-Kerry, are godparents to Warren’s daughter, Abigail.

In 2007, Warren—who had enlisted in the Naval Reserve a few years before—went to Iraq to serve as an intelligence specialist.

Then, Mayor David Cohen announced that he wouldn’t seek re-election, and Warren decided to run. He got a late start, because he had to wait until his tour in Iraq was over to start campaigning.

Warren faced and defeated State Rep. Ruth Ruth Balser in the 2009 mayoral election and would win re-election four years later.

Warren wasn’t always lucky in politics. In 2011, he launched a brief run for the U.S. Senate seat eventually won by Elizabeth Warren. In 2018, he ran in the Democratic primary for governor against former Administration and Finance Secretary Jay Gonzalez, but dropped out due to fundraising challenges.