By CBS13 Staff

SAN JOAQUIN COUNTY (CBS13) — Highway 4 is closed through the Delta due to a big rig accident blocking both directions.

The crash happened a little before 8 a.m. at Tracy Boulevard. Exactly what led up to the crash is unclear, but a big rig ended up overturned.

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Eastbound Highway 4 is now closed at Tracy Boulevard, while westbound traffic is closed at Roberts Road.

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Caltrans says they expect the roadway to be closed until around noon.