TMZ spoke with Randy's brother, Lanny Poffo, who tells us the wrestling legend suffered a heart attack while he was behind the wheel around 10 AM ... and lost control of his vehicle.
Earlier this month, Savage celebrated his 1-year anniversary with his new wife Lynn.
Savage was 58.
Macho Man began wrestling in the WWF in 1985 and became a superstar with his trademark catchphrase "Ooooooh Yeaahhhhh."
UPDATE: Florida Highway Patrol tells TMZ ... Savage was driving his 2009 Jeep Wrangler when he veered across a concrete median ... through oncoming traffic ... and "collided head-on with a tree."
Savage was transported to Largo Medical center, where he died from his injuries.
Savage's wife was a passenger in the vehicle during the collision -- but survived with "minor injuries." She was transported to a different local hospital where she was treated.
R.I.P. Macho Man
