Antonio Cahilig was the operator on the 24 Divisadero route and was heading northbound on Noe Street when he became ill.
According to the SFMTA, the vehicle he was operating hit parked cars, but no one was on board at the time.
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No one else was hurt.
Cahilig was then taken to San Francisco Zuckerberg General Hospital where he died.
"The SFMTA family are grief-stricken at the loss of Antonio," Director of Transportation Jeffrey Tumlin said in a statement. "On behalf of all the staff at the SFMTA, I extend my deepest condolences to Antonio's family and friends. His dedication, and that of all our customer-facing, essential workers, is the pride of our agency."
The man's cause of death at this time is unknown.