LOS ANGELES (CBSLA) — A man who was found clinging to a tree in the middle of the rain-swollen L.A. River was rescued by firefighters near Atwater Village Thursday.

The 50-year-old man was spotted near Colorado Boulevard at about 10:11 a.m., clinging to a tree. Video from Sky 2 showed the river had risen to an unknown depth, LA Fire officials said the water was moving about 15 mph.

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A helicopter lowered a member of the Los Angeles Fire Department’s swift water rescue team to the trees from a helicopter and he emerged carrying the barefoot and bare-legged man at about 10:49 a.m.

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The man was conscious and alert, but LAFD officials say he was suffering from hypothermia. He was taken by helicopter to a hospital in fair condition.

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Heavy rain had swollen the normally dry concrete channel to become a rushing river. The L.A. River is a preferred refuge for some homeless, and swift-water rescues are common when there is heavy rainfall.