THE FAILURE OF THE LOCAL CONTROLLER TO PROVIDE ADEQUATE TRAFFIC ADVISORIES TO N7510H, THE LOCAL CONTROLLER'S IMPROPER CLEARANCE TO N7510H TO DESCEND THROUGH THE TRAFFIC PATTERN, AND THE FAILURE OF THE PILOTS OF BOTH AIRCRAFT TO SEE AND AVOID EACH OTHER. FACTORS WHICH CONTRIBUTED TO THE ACCIDENT WERE THE LOCAL CONTROLLER'S WORKLOAD AND THE EFFECT OF SUNGLARE ON THE PILOT OF N48977.