Gene Hackman 911 Call -- 'Injuries Life-Threatening'

Gene Hackman's injuries were life-threatening after a car struck the actor while he was riding his bicycle in Florida -- this according to the 911 tape, in which the dispatcher also calls the accident a "hit-and-run."

According to the caller, Gene lost consciousness after the car hit him -- and was bleeding from multiple places.

Later in the call, it sounds as if Gene regains consciousness -- but won't cooperate with bystanders who are asking him to stay still.

The dispatcher calls the accident a "hit-and-run" -- but law enforcement sources tell TMZ, that was a mistake ... the woman who struck Gene stayed on the scene and cooperated with authorities.