NORWALK, Conn. — Donald J. Irwin, a Norwalk Democrat who served three terms in Congress, two years as state treasurer, and four years as mayor of his hometown, died of heart problems Sunday while in hospice care at his home, his wife, Janet, said. He was 86.
He held the Fourth Congressional District seat representing southwestern Connecticut for three terms, from 1959 to 1961 and from 1965 to 1969.
A year after losing his 1960 reelection bid to Abner Sibal, a Republican, Mr. Irwin was appointed state treasurer by Governor John Dempsey, to finish the term of John Speziale, who left office to become a judge. Mr. Irwin won back the congressional seat in 1964 by beating Sibal and was reelected in 1966.
He lost the 1968 election for the House seat to Lowell P. Weicker Jr., the future US senator and Connecticut governor.
Mr. Irwin returned to his law career served two terms as Norwalk mayor from 1971 to 1975.
‘‘Connecticut lost a faithful public servant and a man known for his integrity and dedication to his state and country,’’ US Representative Jim Himes, a Connecticut Democrat, said in a statement.
Governor Dannel P. Malloy told The Hour of Norwalk that he knew Mr. Irwin as a child and always admired Mr. Irwin’s work.
‘‘He was a straight-shooter and told you what was on his mind,’’ Malloy said. ‘‘He was that kind of guy.’’
Mr. Irwin was born in 1926 in Argentina to American parents, according to his official congressional biography. Shortly after beginning undergraduate studies at Yale University in New Haven in 1945, Mr. Irwin left school to serve in the US Army in Brazil for the Joint Brazil-United States Military Commission.
After his military service, he returned to Yale, earned his bachelor’s and law degrees and became a lawyer. He also served on the Norwalk Board of Education before winning election to Congress.