20 Injured in Tourist Bus Crash Near S.F.'s Union Square

A double-decker tourist bus careened wildly out of control Friday in San Francisco's crowded Union Square, running down a bicyclist, at least two pedestrians and striking several cars before it plowed into scaffolding lining a construction site. Twenty people were hurt, including six critically.

Twelve people suffered minor injuries in the crash that happened just before 3 p.m., San Francisco Fire Chief Joanne Hayes-White said. The others suffered moderate injuries.

Union Square was crowded with shoppers and tourists when, according to eyewitnesses, the bus came roaring across two city blocks at a high rate of speed. It struck several moving vehicles in its path as well as the bicyclist and the two pedestrians, the latter ending up trapped underneath the vehicle after it plowed into the scaffolding.

It also knocked down several power lines.

Firefighters had to extricate the two people under the bus as well as one trapped on the top deck, Hayes-White said. As many as 30 people were believed to have been on board when the vehicle went out of control, officials said.

The driver was conscious and able to speak when firefighters pulled him from the wreckage, Hayes-White said. But she added it was too early to speculate about what caused him to lose control.

"The police department will investigate what those circumstances involved, whether it was mechanical failure, whether it was driver error. It's way too early to tell right now," she said.

Muni buses were re-routed around the area.

KQED's Amanda Font and the Associated Press contributed to this report.