Officials have determined ex-NFL player Keion Carpenter died from traumatic brain injuries suffered in a fall during his Miami vacation ... but why he fell remains a mystery.
TMZ Sports obtained the autopsy report for the 39-year-old former Atlanta Falcons safety who died on Dec. 29th.
Investigators say Carpenter had only had 1 drink on the day he collapsed (rum and pineapple juice) during an excursion with his family to Black Point Marina.
When they were leaving at 8:15pm, he raced his son to the car ... and that's when Keion came to a complete stop by his car, grabbed the side mirror and collapsed backwards to the ground.