Twenty people were injured, six critically, when a double-decker tour bus suddenly veered off the road in San Francisco's Union Square, running down a bicyclist, at least two pedestrians and striking several cars before careening into scaffolding lining a construction site, fire officials said.
Twelve people suffered minor injuries while the remaing eight suffered moderate injuries, San Francisco Fire Department spokeswoman Mindy Talmadge said, according to the Associated Press.
Talmadge said that the incident started at around 3 p.m. local time. Eyewitnesses reported that the bus came speeding across two city blocks at a high speed. It struck several moving vehicles on its path, as well as the bicyclist and the two pedestrians, who wound up trapped beneath the vehicle after it crashed into the scaffolding, ABC News reported.
It also knocked down several power lines used to propel the city's iconic electric buses.
One rider who was on the upper level of the double decker bus was critically injured and had to be extricated by firefighters. The driver was also hurt, and as many as 30 passengers were believed to be onboard at the time of the crash, officials said, according to Reuters.
Despite being hurt, the driver was conscious and was able to talk to firefighters when he was rescued from the wreckage. However, he was unable to provide authorities with any insight about the cause of the crash.
Authorities are still investigating and analyzing every possible angle, including mechanical or driver error.
The police department couldn't immediately be reached for comment.