SAN JOSE -- Big rig crashes transformed Friday morning's commute in both San Jose and across the Richmond-San Rafael Bridge into a nightmare as traffic was brought to near standstill while crews tried to remove damaged vehicles.

At least five vehicles crashed on the bridge around 7:30 a.m. today, according to the California Highway Patrol.

The collision was reported at 7:37 a.m. on the incline just west of the toll plaza and involved two small delivery trucks and up to four other vehicles, CHP Officer Peter Van Eckhardt said.

One person suffered minor injuries, according to Van Eckhardt.

A Sig-alert was issued at 8:04 a.m. and traffic is reportedly backed up at least 2 miles, Van Eckhardt said.

Meanwhile, in San Jose an overturned big rig blocked several lanes of northbound U.S. Highway 101 near Blossom Hill Road, tying up commute traffic for miles.

According to the California Highway Patrol, the crash sent debris across lanes No. 1 and 2 of the busy freeway at about 3 a.m., Van Eckhardt said.

A Sig-Alert was issued and traffic began to back up for the four hours it took to clear the crash. The driver suffered only minor bumps and bruises.

Authorities were looking at several possible causes of the crash including that a blown tire or the driver falling asleep at the wheel.

All four lanes of the busy freeway were re-opened around 7 a.m.