At Tesla, Elon Musk casts himself as a superhero. But he sweats the details on the factory floor.

Tesla's race to build the Model 3 has made its Fremont factory one of the most widely watched production facilities in the world. The company has no formal organizational chart beyond a list of top leaders. California's workplace-safety watchdog has opened a third investigation into factory conditions. Musk recrafted the car company into the mold of a sci-fi wonderland. It produced only two cars, the Models S and X, from a single plant at prices only the wealthy could afford. A third name, senior vice president of engineering Doug Field, was recently removed after the company said Monday he was “moving on” following a weeks-long leave of absence.