Larry Rasky, one of Boston’s preeminent public relations gurus and a close confidant of former Vice President Joe Biden, died Sunday morning, according to three people close to Rasky and his company.

Rasky, 69, was the chairman and CEO of Rasky Partners, and had more than 30 years in the public relations business with offices in Boston and Washington.

Friends and co-workers said that in recent weeks Rasky had been extremely active with both business and his work helping to run a super PAC supporting Biden’s presidential bid.

“I’m devastated, absolutely devastated,” said Therese Murray, the former president of the Massachusetts Senate who went to work with Rasky after her career at the State House ended. “He was just a great guy, really. He had integrity and treated everyone so well. No matter who you were he treated everyone with respect. This is going to be really hard on his family and his work family.”

The cause of death is unknown.

“Larry was a giant in so many ways, not just professionally but personally. He loved and was loved by so many. He always treated the company like a family and we are all shocked and saddened by the news of his passing. He has left an indelible imprint on everyone he touched and the company that bears his name will go on in his spirit,” the company said in a statement.

Executives of the firm said that Rasky had been extremely busy in recent weeks “trying to get his friend elected president,” while they carried on with the day-to-day business for a roster of clients that includes Massachusetts General Hospital, Boston Medical Center, BJ’s Wholesale Club, Citizens Financial Group and Harvard Pilgrim Health Care.

Rasky was a long-time advisor to Biden and served as press secretary of the Delaware Democrat’s 1988 presidential campaign.

Last fall, Rasky helped to launch the United the Country super PAC to support Biden’s most recent 2020 campaign and served as its treasurer.

A memorial will be planned for a later date, said one official, when people can gather again to celebrate his life.