Officials say the bus crossed the median and was facing oncoming traffic on Lombard when it crashed into a dry cleaners around 5:45 a.m.
The bus driver is facing life-threatening injuries.
VIDEO: Dashcam video shows SF Muni bus crash into building
Incredible new surveillance video shows the exact moment the Muni bus, which was carrying passengers, crashed into the building.
Davonte Robinson saw the whole thing from across the street. "It was driving on this side and then went over. It was slow though, as though he let off the gas and it coasted over and coasted slowly into the building and the tree. And the tree snapped. That's when I heard the loud thunder," he said.
Investigators say one passenger complaining of pain was taken to the hospital but the most seriously hurt was the 66-year-old bus driver.
Passengers stumbled off the bus, one falling while trying to get out. Police would like to interview those who were on board.
"The others left the bus and continued on their way, wherever it was that they were going this morning. If they see reports of this collision, we would like them to contact investigation," SFPD Sgt. Michael Andraychak said.
SFMTA Spokesperson tells me bus crossed over median, 4 total on bus, Driver and 3 passengers. Driver in critical condition at SF Gen, passengers had minor injuries, no known pedestrians on sidewalk pic.twitter.com/FBkxJl4Y1I— Melanie Woodrow (@MelanieWoodrow) September 10, 2018
Investigators say it's too early to speculate on why the bus crossed the median and crashed. They will be reviewing the video captured by the bus' camera.
The accident had a huge impact on morning traffic - westbound Lombard Street was shut down all morning.
Those staying in hotels near the scene were just stunned that this happened. "Everybody is coming out of their rooms, everybody is looking around and coming out of their rooms. It is a crazy thing to see," Robinson said.
Muni officials say the bus driver's family is with him at the hospital. They still don't know what caused the crash.
Surveillance video of the San Francisco bus crashing this morning on Lombard Street. pic.twitter.com/5MMnMJ2CEb— Amy Hollyfield (@amyhollyfield) September 10, 2018
Here’s more video of the bus being moved pic.twitter.com/FsAcfY3w5m— Melanie Woodrow (@MelanieWoodrow) September 10, 2018
The city is definitely working to get this cleaned up quickly pic.twitter.com/n2yGNVOvRT— Melanie Woodrow (@MelanieWoodrow) September 10, 2018
San Francisco Muni bus crashes on Lombard. Bus driver has life threatening injuries. pic.twitter.com/iR8Uc8lGda— Amy Hollyfield (@amyhollyfield) September 10, 2018