It has been suggested that the cause may never be found, I think that is now highly likely. However historically as only about 10% or less of air crashes are caused by high jack or suicide then it has to be assumed that an aircraft malfunction has occurred. As such the travelling public are going to be very unhappy climbing aboard a B777 with a mechanical flaw. Boeing will try to pretend its not their machine but truth usually comes out. Its in their interest to press for a discovery of the reason. If there is a repeat it will lead to a grounding of the a/c. look what happened to the Comet.