ordered emergency inspections of 135 older 737s. as jeanne meserve reports from washington more than 500 aircraft of the same design as the one that ripped open. >> reporter: this is a southwest 737, and the rupture occurred on the left side over here. >> reporter: the national transportation safety board investigation into what caused a roof to rip on friday night is still in its early stages. the torn section of fuselage is now back in washington for nal at an ntsb origin. >> we have to identify it and what design this aircraft might have to others. >> reporter: the federal aviation association is inspecting planes.