Updated: 3:50 p.m.

Former Sen. John Durkin (N.H.), a Democrat who won the closest election in Senate history, has died, according to the office of Sen. Jeanne Shaheen (D-N.H.). He was 76.

The New Hampshire Veterans Home, which Shaheen’s office said announced the news of Durkin’s death, did not immediately return a request for comment on the cause, manner or date of Durkin’s passing.

Durkin — who ran for an open Senate seat in the Granite State after longtime Republican Sen. Norris Cotton announced his retirement — was given virtually no chance in the then-strongly Republican state. His Republican challenger, then-Rep. Louis Wyman, was heavily favored.

But on Election Day 1974, Wyman was pronounced the winner by 355 votes out of more than 200,000 ballots cast.

Durkin demanded a recount, which switched the outcome, giving the Democrat a 10-vote margin of victory that sparked a nearly yearlong ordeal that left New Hampshire without a second Senator and gained national media attention.

After a third recount declared Wyman the winner by two votes, the Democratic-led Senate refused to seat him and declared the seat vacant. Durkin and Wyman then squared off in a September 1975 special election that Durkin won by more than 27,000 votes.

A Navy veteran from Worcester County, Mass., Durkin served on the Senate Veterans’ Affairs Committee and was instrumental in extending GI Bill benefits to veterans of the Vietnam War.

Before his time in Congress, he served as assistant attorney general of New Hampshire from 1966 to 1968, as well as state insurance commissioner from 1968 to 1973, when he began running for the Senate, according to his official Congressional biography.

He lost his 1980 re-election bid to Republican Warren Rudman and returned home to Manchester to practice law. In 1990, he lost another Senate bid, to GOP Rep. Bob Smith.

Shaheen, the first Democrat to serve as a New Hampshire Senator since Durkin left office, praised his service.

“John Durkin was a longtime friend to me personally and to all working men and women in the New Hampshire,” Shaheen said in a statement. “John was a colorful and authentic public servant, and I will miss his quick wit and dedication to serving the underdog. My thoughts and prayers are with the entire Durkin family.”

Sen. Kelly Ayotte (R-N.H.), who holds the seat Durkin once held, said she is mourning Durkin’s loss.

“From the Navy, to state government, to Capitol Hill, he devoted much of his life to public service,” she said in a statement. “There’s no question that his 1974 Senate race will remain as one of the more compelling chapters in New Hampshire history. My thoughts and prayers are with Senator Durkin’s family and friends during this sad time.”

New Hampshire Gov. John Lynch (D) also expressed sadness at the news of Durkin’s death.

“John Durkin dedicated much of his life to public service,” Lynch said in a statement. “He served the people of New Hampshire well at the state level and in the U.S. Senate, where among other issues, he worked to ensure our veterans received the benefits they deserved. His passing is truly a loss for New Hampshire.”