Boeing stock was wavering 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 cause of the Air India Boeing jet’s crash is unknown, but it comes amid the plane maker trying to rebuild trust on safety issues.