WAS DRIVING ON A HIGHWAY DURING INCLEMENT CONDITIONS CONSISTING OF LIGHT TO MODERATE RAINFALL/TOTAL DARKNESS AND FOGGY, VEHICLE'S LIGHTS WERE ON LOW BEAM. THE HEADLIGHTS SUDDENLY WENT OUT, VEHICLE WENT OUT OF CONTROL, APPLIED BRAKES B UT THEY DIDN'T WOTK, VEHIVLE HIT A ROCK WALL. DURING INSPECTION, IT WAS NOTED THAT BRAKE PADS AND ROTORS WERE WORN OUT. BOTH DRIVER/PASSENGER SUSTAINE DINJURIES. *AK