DRIVING 60MPH. HEARD POPPING NOISES. VEHICLE UNCONTROLLABLE. WENT OFF ROAD & DOWN 30FT EMBANKMENT & FLIPPED OVER TWICE. MECHANIC CHECKED & NOTICED LEFT FRONT LOWER BALL JOINT HAD FALLEN OUT. THIS CAUSED A LOSS OF CONTROL. 4 PEOPLE WERE INJURED & EVERYONE WAS WEARING SEAT BELTS. *AK