A man in his 30s suffered life-threatening injuries after being punched on San Francisco's Market Street on Monday evening, according to police.
The assault was reported at 7:19 p.m. in the area of Market and Jones streets.
The victim fell to the ground after being punched. He was taken to a hospital and an update on his condition was not immediately available this morning.
The suspect, also believed to be a man in his 30s, has not been arrested, police said.