Boeing stock dropped on Wednesday as investors slowly pieced together what happened to the 787 jet that crashed in India almost a week ago.Investigations are focused on the engines and why the plane lost lift shortly after takeoff.

Last year, the F.A.A. said it was also investigating claims by a Boeing engineer that parts of the fuselage, or body, of the Dreamliner were improperly fastened together, which the whistle-blower said could cause premature damage to the plane over years of use.

The crash of an Air India Boeing 787 Dreamliner seconds after takeoff from Ahmedabad city, killing all but one of the 242 people on board, is the world's worst aviation disaster in a decade. At least 30 people were also killed on the ground as the airliner crashed into a medical college hostel near the airport.