RIVERSIDE (CBSLA.com) — Authorities say a man has drowned during a backyard pool party in Riverside.

The incident happened around 10 p.m. Saturday in the 1600 block of Southport Drive.

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Police said the victim in his 20s was pulled from the bottom of the pool by someone at the party and CPR was administered by paramedics.

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The unidentified man was declared dead at an area hospital.

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Police said alcohol was involved.