CONTA COSTA COUNTY (CBS SF) — A man killed Friday morning in a rollover crash on northbound Interstate Highway 680 east of Martinez was not wearing a seatbelt.

The crash was reported shortly before 7 a.m. just south of the Pacheco Boulevard off-ramp, a California Highway Patrol spokesman said.

The man, who has not been identified, was ejected from his silver Buick as it rolled several times following a crash with another vehicle, CHP Officer John Fransen said.

Fransen said the Buick ended up in a field near the freeway. He did not know if the driver of the other vehicle was injured.

The cause of the crash is under investigation.

The crash closed several northbound lanes of the highway, but all lanes have since been opened.

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