U.S. Sen. Maria Cantwell will hold Congressional hearings to investigate the “root cause” of “safety lapses” that led a piece of fuselage to blow out of a Boeing 737 Max 9 aircraft midflight. Cantwell, chair of the Senate Committee on Commerce, Science and Transportation, announced the investigation after she met Wednesday with Boeing CEO Dave Calhoun. There is not a date set for the proceedings yet. “The American flying public and Boeing line workers deserve a culture of leadership at Boeing that puts safety ahead of profits,” Cantwell, D-Washington, said in a statement, adding that she made …