ALTADENA (CBSLA) — Some off-duty Marines hiking at Switzer Falls north of Altadena jumped into action to help a nearby hiker experiencing chest pains.

Montrose Search and Rescue was notified at about 4 p.m. Sunday that a hiker was experiencing chest pains on the Switzer Falls Trail.

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The hiker had used a personal locator beacon to alert authorities. But he still needed help getting off the five-mile trail, which is often described as difficult and very steep.

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As local authorities worked their way downstream to the man, they found he had been carried upstream by four off-duty U.S. Marines from Camp Pendleton. The Marines had taken him further up the trail for a more rapid rescue, according to the Los Angeles County Sheriff’s Department.

The hiker was airlifted to a local hospital, where he is expected to recover.

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(© Copyright 2018 CBS Broadcasting Inc. All Rights Reserved. City News Service contributed to this report.)