People pinned inside tour bus after crash in San Francisco

A double-decker tour bus with as many as 30 people on board crashed in a busy shopping district on Friday afternoon, leaving multiple people injured.

Police say a careening tour bus that smashed into a bicyclist, several cars and a construction site in tourist-packed Union Square has left 19 people hurt – 5 of them with life-threatening injuries.

The fire chief says it’s too early to determine whether driver error, a mechanical problem or other issues caused the accident.

Officials say that the crash happened when the bus lost control, struck a pedestrian and bicyclist, crashed into several cars then slammed into a construction site. The scaffolding collapsed onto the sidewalk.

Six people were in critical condition, 12 were transported to area hospitals with various injuries and two were treated on the scene, said San Francisco Police Sgt. Michael Andraychak.

Update, 4:15: According to a statement by SFPD spokesman Officer Albie Esparza, several witnesses said the bus was traveling at a high rate of speed.

KRON4 producer Shannon Adams was on the scene at the time of the crash.

Crews are working carefully around downed power lines to reach the injured passengers. Our reporter on the scene notes that one injured person was extracted from the roof of the bus.