Tracy Morgan The Sundance 911 Call 'He's Lost Consciousness'

TMZ has obtained the 911 call placed moments after Tracy Morgan fell unconscious yesterday at the Sundance Film Festival.

According to the caller -- who identifies Tracy as "a celebrity" on the phone -- the actor had a high fever, and was in possession of antibiotics for an infection in his foot. His breathing was "not normal." The caller says he's not sure if Tracy had been drinking.

TMZ broke the story -- Morgan was rushed to the hospital last night after delivering an acceptance speech at the Creative Coalition Spotlight Awards, after the actor lost consciousness.

Multiple eyewitnesses claim Morgan was slurring his words during the event and appeared extremely intoxicated -- but a rep for the hospital where Morgan was subsequently treated insists ... neither drugs nor alcohol were found in the actor's system upon medical evaluation.

Morgan tweeted moments ago, claiming the high altitude was to blame for his medical emergency.