Rob Bironas -- Wasted the Night of Fatal Accident

Ex-Titans kicker Rob Bironas was hammered -- with a blood alcohol content njearly 3 times the legal limit -- the night he wrecked his SUV and died in Nashville.

The toxicology report shows Bironas' BAC was .218 when he died on September 20. Police released test results to his family today. The report also revealed he died from blunt force trauma ... and had a small amount of Diazepam (Valium) in his system.

Rob's wife, Rachel -- who is Terry Bradshaw's daughter -- told police Rob might have had one beer at home that night ... before he unexpectedly took off in his vehicle without telling her.