FAILURE OF BOTH PILOTS TO PERFORM ADEQUATE VISUAL LOOKOUT DURING TAXI, AND THE GROUND CONTROLLER'S FAILURE TO IDENTIFY THE POSITION OF THE PIPER PA-34 BEFORE ISSUING TAXI INSTRUCTIONS. FACTORS RELATING TO THE ACCIDENT WERE: DECREASED VISIBILITY DUE TO DARKNESS AND RAIN, PARTIAL FAILURE OF ATC EQUIPMENT DUE TO A LIGHTNING STRIKE, AND DIVERTED ATTENTION OF ATC PERSONNEL DUE TO THE PARTIAL FAILURE OF ATC EQUIPMENT.