CONCORD (CBS SF) — Unsafe speeds led to a collision that six vehicles ended up involved in Friday morning on state Highway 4 in Concord, according to the California Highway Patrol.

The collision, which was reported at 5:54 a.m. on Highway 4 near Willow Pass Road, began when a Honda Civic traveling at an unsafe speed rear-ended a Saturn Ion, CHP Officer Brandon Correia said.

The two vehicles began to veer out of control and four approaching vehicles — a Dodge car, a Ford van, a Chevrolet SUV and a Dodge pickup truck — crashed while trying to avoid the vehicles.

Five people were taken to the hospital with minor injuries as a result of the collision, Correia said.

The two vehicles that initially collided had an occupant each who suffered injuries. The three others were occupants of the Dodge car.

Ten people in all complained of pain but half declined to be taken to a hospital and were treated by paramedics at the scene, according to the Contra Costa County Fire Protection District.

The collision caused an extensive backup on Highway 4 and side roads between 6 a.m. and 7:10 a.m., as two lanes were blocked on the highway during that time, Correia said.

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