DETROIT (June 10, 2014) — General Motors Co.'s investigation into its mishandling of a fatal defect spreads blame among dozens of employees at various levels, but it bluntly says the problem began — and remained unfixed for years — largely because of a "single engineer." The report condemns GM's infamously slow-moving bureaucracy and lack of individual accountability, while also explaining how one relatively low-level employee can precipitate a crisis that now threatens to cost the auto maker billions of dollars. The engineer, Ray DeGiorgio, who has been fired by GM, approved an ignition switch that he knew to be flimsy, secretly authorized changing it years later, then "misled" coworkers who were looking into crashes and customer complaints, the inquiry found. Mr. DeGiorgio, a 23-year GM veteran, is mentioned 207 times in the 325-page report by former federal prosecutor Anton Valukas, including in the very first sentence.