A massive helicopter is being used today to help to rebuild transmission towers damaged by a gas explosion in Center Township. West Penn Power officials say the helicopter will carry steel tower sections to replace one of the company’s transmission towers damaged during last month’s massive gas explosion. The pre-assembled tower sections will be taken to the foundation about one mile away just off Bunker Hill Road in Center. Officials say six 500-kilovolt towers were either damaged or destroyed by the early morning blast. Officials say crews have already replaced most of the towers, but because of the rugged terrain, a helicopter is needed to replace the remaining tower.