The race began with a swim of just under a mile off Venice Beach.
Three people were taken to the hospital, including a lifeguard hurt during a water rescue.
One person nearly drowned, while a second swallowed sea water into her lungs.
Meantime, several streets along the race route remain closed, including Venice Boulevard from the ocean to Fairfax Avenue. Also, part of Olympic Boulevard and surrounding downtown streets are closed.
The race consists of a near-mile swim off Venice Beach, followed by a 24-mile bike ride and a 10-kilometer run through downtown, ending at L.A. Live.
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