ALAMO (CBS SF) — A multi-car collision Thursday morning blocked all but one lane of northbound Interstate Highway 680 in unincorporated Contra Costa County in Alamo for over an hour, according to the California Highway Patrol.

The crash was reported at 11:23 a.m. on northbound Highway 680 near Livorna Road and involved up to seven vehicles, CHP officials said.

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An ambulance responded to the scene but information about possible injuries was not immediately available from the CHP.

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The crash was blocking the three left northbound lanes of the four-lane highway as of shortly before noon, according to the CHP.

Authorities issued an update at around 12:43 p.m. that said all lanes had been cleared. Drivers should expect residual delays.

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