the explosion is believed to be caused by natural gas and plumbing bourque. we will have a live report from that scene coming up in less than ten minutes. >> investigators have gone through the apartment and parents' home of the co-pilot of the germanwings flight that crashed into the french alps on tuesday looking for evidence on why he would intentionally crash their plane. officials say a cockpit voice recorder shows andre us lubitz locked the pilot off the out cockpit after he went to the rest room. he then sent the plane into a dive into the alps. pounding on the door could be heard as passengers scream. they don't believe it is linked to terrorism or politics. >> we have learned a second american on board that plane has local ties. yvonne selke then known as yvonne carlo, graduated from springfield high school in delaware count any 1975. one of her friends says she's going to miss her at their 40th annual class reunion in october. >> tough getting older but then, with this horrific situation, i mean, i can't even fathom. >> her daughter em lee also died