WHILE SITTING IN PARK AT IDLE RPM I HEARD A LOUD THUMP FROM THE ENGINE COMPARTMENT WHICH WAS FOLLOWED BY AN ELECTRICAL SYSTEM WARNING AND AN ENGINE OVERHEAT WARNING. I TURNED OFF THE VEHICLE IMMEDIATELY AND HAD VEHICLE TOWED TO MY MECHANIC. WHEN CARE ARRIVED AT MECHANICS SHOP THE CRANKSHAFT PULLEY LITERALLY FELL OFF THE CAR. UPON INSPECTION THE CRANKSHAFT PULLEY EXPERIENCED A COMPLETE FAILURE THAT RESULTED IN TOTAL DESTRUCTION OF THE ENGINE. ENTIRE ENGINE NEEDS TO BE REPLACED DUE TO EXTENSIVE VALVE/ENGINE DAMAGE.