On Saturday in Bourne, Mass. two utility workers from MassBay Electrical Corp. were killed onsite while working on high voltage electricity lines for NSTAR when their boom truck tipped over, WBZ-TV reports.  They were working on lines at Cape Cod Aggregates Corp., on Scenic Highway (Route 6). The workers were about 150 feet in the air in the truck’s aerial basket when the boom fell to the ground, flipping the truck on its end. The men died on impact, the police said.  Bourne Police and Fire departments responded to the accident site Saturday, as did a representative from OSHA.Cape and Island District Attorney, state police, and OSHA will open investigations to find out if any safety violations may have caused this tragic accident.  OSHA may take up to six months to complete its investigation into the accident.The two men who were killed in the accident have been identified as Joseph L. Boyd III of Fall River, Mass., and John Loughran of Quincy, Mass.Our heartfelt condolences go out to the Loughran and Boyd families as they mourn the loss of their beloved sons.