Aviation experts said the risk the plane was brought down by lightning was slim.
"Lightning issues have been considered since the beginning of aviation. They were far more prevalent when aircraft operated at low altitudes. They are less common now since it's easier to avoid thunderstorms," said Bill Voss, president and CEO of Flight Safety Foundation, Alexandria, Va.
He said planes have specific measures built in to help dissipate electricity along the aircraft's skin.
"I cannot recall in recent history any examples of aircraft being brought down by lightning," he told The Associated Press.