Chain reaction accident between a MUNI bus and two dump trucks

SAN FRANCISCO (KGO) -- San Francisco police say a dump truck on Geary Boulevard slammed its brakes in traffic Friday afternoon, causing a MUNI bus driver to in turn slam his brakes, but the bus ended up hitting another dump truck.

When the bus slammed into the dump truck, one passenger told ABC7 News some people were thrown on the floor.

A MUNI spokesman said a total of 20 people were injured. Twelve people were taken to local hospitals, but all were released by Friday night. Eight people were treated on the scene.

The front window of the MUNI bus shattered upon impact, leaving glass scattered everywhere.

A MUNI spokesperson says the bus driver was questioned by police and will be tested for drugs and alcohol, which is standard in these investigations.