U.S. investigators looking into the Southwest Airlines accident that left one passenger dead are focusing their probe on the plane's left engine,... where a fan blade broke off and burst out of the casing.<br /> According to the head of the U.S. National Transportation Safety Board on Wednesday,... the engine showed signs of metal weakness at the point where the blade broke off. <br />This parallels a similar incident on a Southwest flight in 2016,... where a turbine blade snapped off,... forcing the pilot to make an emergency landing. <br />Both incidents involved engines manufactured by the same company, CFM International.<br />Over six-thousand planes dotted around the world equipped with the same model. <br />
