Sweeping failures by Boeing engineers, deception by the company and significant errors in government oversight led to the two fatal crashes of the 737 Max, congressional investigators have concluded. A 245-page report issued Wednesday provides the most scathing account so far of the miscalculations that led to 346 deaths, the grounding of Boeing’s best-selling jet and billions of dollars in losses for the manufacturing giant. “The Max crashes were not the result of a singular failure, technical mistake or mismanaged event,” the report by the House Transportation and Infrastructure Committee said.