CALABASAS (CBSLA.com/AP) — Authorities say a 1,000-pound sign fell on a worker at a Southern California gas station, leaving him with serious leg injuries.

City News Service says it happened shortly before 11 a.m. Friday at a Mobil station in Calabasas.

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Los Angeles County fire Inspector Keith Mora says the worker was trapped for about 20 minutes before he was freed.

The worker was subsequently airlifted to a hospital just after 11:05 a.m., the Los Angeles County Fire Department confirmed to CBSLA.com.

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It’s unclear why the sign fell.

No further information was immediately available.

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