The National Transportation Safety Commission's investigation into Boeing has been unsuccessful: important records are missing and no operational records can be found. On the 13th, the chairman of the National Transportation Safety Commission, Jennifer Hormendy, wrote to Congress that the investigation into Boeing has not progressed smoothly and has not yet obtained some necessary information from Boeing, including a surveillance video of a maintenance operation. In addition, the National Transportation Safety Commission requested monitoring footage of the factory from Boeing to obtain information about the workers at the time, but Boeing claimed that that footage had been covered by subsequent video footage.