Abstract: AT ABOUT 3:30 PM ON OCTOBER 28, 1986, EMPLOYEE #1 AND ANOTHER EMPLOYEE WERE INSTALLING BUILT-UP ROOFING ON A ROOF WITH 11 ROOF OPENINGS. EACH OPENING WAS 67 1/8 INCHES BY 74 1/2 INCHES. EMPLOYEE #1 FELL THROUGH ONE OF THE ROOF OPENINGS TO A CONCRETE SURFACE 18 FEET BELOW. HE SUFFERED SEVERE HEAD INJURIES WHICH REQUIRED HIS EVACUATION TO A HOSPITAL. HE DIED THERE TWO DAYS LATER WITHOUT REGAINING CONSCIOUSNESS. THE SECOND EMPLOYEE, ALTHOUGH WORKING WITHIN 10 FEET OF EMPLOYEE #1, HAD HIS HEAD DOWN AND DID NOT OBSERVE EMPLOYEE #1'S ACTIONS UNTIL HE HEARD HIS NAME CALLED. BY THEN EMPLOYEE #1 WAS ALREADY FALLING THROUGH THE ROOF OPENING.