The worker, a 23-year-old who lives in West Philly and now works at a school, said he was hustling to learn about the hundreds of items on the carousel, all the different types of diapers and syringes. (Each type of item, regardless of how many are ordered, constitutes one “line.”) He got two 15-minute breaks during his overnight shift, but he said he realized he couldn’t afford to take them. He knew he could move faster unpacking boxes of supplies and setting them up on the carousel’s shelves, to which he’d later return as orders came through, but that would mean sacrificing accuracy for speed — and he didn’t want to be sloppy.