San Francisco Board of Supervisors President London Breed said Mayor Edwin Lee has died. He was 65.

Breed said early Tuesday that Lee passed away just after 1 a.m. at Zuckerberg San Francisco General Hospital.

“It is with profound sadness and terrible grief that we confirm that Mayor Edwin M. Lee passed away on Tuesday,” a statement from the mayor’s office said.

The statement said family, friends and colleagues were at Lee’s side.

Lee was not known to be ill. No other details have been released.

Lee was appointed as mayor in 2011, replacing Mayor Gavin Newsom, who was elected the state’s lieutenant governor. He went on to win the 2011 election and was re-elected in 2015.

He was known for his work against homelessness.

Breed assumes the role of acting San Francisco mayor.