A quarter of the Fisherman’s Wharf pier “was lost in flames,” according to the San Francisco Fire Department PIO.
No injuries were reported. The pier has been completely evacuated, according to the ministry.
Flames could be seen in the morning darkness on photos tweeted by Dan Whaley.
The fire was first reported at 4:17 a.m. local time (7:17 a.m.ET) and was confined to one section of the pier.
The fire department tweeted a link to live updates.
Officers report that the fire caused the building to partially collapse on the south side of the pier, has spread to two buildings on the pier, and is likely to spread to a third, the fire department said.
There is still no word for a cause.
Firefighter St. Francis was put in place to protect the historic SS ship Jeremiah O’Brien built during World War II, and he successfully saved the ship from damage, said department spokesman Jonathan Baxter.
Several fire boats are positioned around the wharf and help fight the fire.