OAKLAND (CBS SF) — A multi-vehicle chain reaction crash shut down the No. 3 bore of the Caldecott Tunnel Monday morning for nearly an hour, slowing commute traffic into Oakland and San Francisco, authorities said.

The California Highway Patrol reported the crash at around 11:17 a.m. in the newest of the westbound Highway 24 bores. Several vehicles involved were about to make it off the freeway at the Broadway exit, but others remain blocking the No. 3 bore.

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A Sig alert was issued at 11:35 a.m. due to the crash, which occurred just west of the tunnel near the Tunnel Road on-ramp, according to the CHP.

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All westbound traffic was diverted to the other bores and traffic reportedly was backed up. Two people were hospitalized with minor injuries suffered in the crash, according to the CHP.

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The CHP said a fleet of tow trucks were able to remove the damaged vehicles and the bore was reopened at 12:20 p.m.