In a statement, Gov. Phil Murphy called his fellow Democrat a “steadfast champion for the people of New Jersey.”

“With his signature bowtie, big heart, and tenacious spirit, Donald embodied the very best of public service,” Murphy said in a statement. “As a former union worker and toll collector, he deeply understood the struggles our working families face, and he fought valiantly to serve their needs, every single day.”

Payne had previously served as president of Newark City Council in New Jersey’s largest city, and on the Essex County Board of Commissioners.

Payne’s office had said his heart attack was connected to complications from diabetes. Payne’s father, Donald Milford Payne, held the congressional seat before him. When the elder Payne died in 2012, his son ran successfully in a special election to succeed him.

He had won reelection six times since. The district covers parts of Newark and its heavily populated suburbs.

A New Jersey colleague, Democratic U.S. Rep. Frank Pallone, called Payne a “truly great public servant” who liked to call him “Uncle Frank” and had fought to raise awareness for diabetes and colorectal cancer prevention and to replace lead pipes in Newark.

Payne’s survivors include his wife, Beatrice, and their three children, Murphy said.