One of the contestants from "Biggest Loser" Season 9 is listed in critical condition at a San Francisco hospital, TMZ has learned, after plummeting several stories from a building on September 3rd.

It's unclear how he fell,  but sources close to Sam Poueu tell us he suffered a pelvic injury, torn ligaments, a punctured lung, and a broken leg during the accident.

According to sources, Sam, who was a fan favorite on the show last year, is currently recovering in the ICU.  But while he's listed in critical condition, we're told he can still recognize visitors.

Dr. H from "Biggest Loser" tells us, he can't make specific comments about Sam's current condition, but claims Sam is doing better every day.