TRAVELING SOUTHBOUND ON INTERSTATE 15 I CHANGED LANES FROM THE RIGHT HAND LANE INTO THE RIGHT HAND MERGE/EXIT LANE TO FRIAR RD EXIT. I WAS ON MY WAY TO CHURCH ABOVE MISSION VALLEY. I WAS TRAVELING AT APPROXIMATELY 60 MILES PER HOUR, AS I WAS CHANGING LANES THE STEERING WHEEL SUDDENLY NO LONGER CONTROLLED THE WHEELS. I MOVED THE STEERING WHEEL ONLY ENOUGH FOR A LANE CHANGE BUT THE STEERING LOST ALL CONNECTION WITH WHEELS. THE FRONT WHEELS APPEARED TO HAVE LOST CONNECTION WITH THE STEERING, THE CAR LURCHED FIRST LEFT THEN RIGHT, I PUT MY FOOT ON THE CLUTCH TO TRY TO GET IT TO SLOW DOWN. I DIDN'T HIT THE BRAKES WHILE CAR WAS IN UNCONTROLLED MOVEMENT. THEN THE CAR DID AT LEAST ONE COMPLETE 360 SPIN, CAME OUT OF THE SPIN FACING THE CURB AT THE SHOULDER, BOUNCED OVER THE CURB. APPARENTLY IT MAY HAVE GONE AIR BORNE AND SHEARED OFF A SMALL TREE. WENT DOWN THE EMBANKMENT ON ITS WHEELS AND ENDED UP AT THE BOTTOM STILL ON ITS WHEELS. *TR