Like generations of New Orleans residents, 53-year-old Ruben Williams had known only one kind of health care before Katrina ravaged the city in 2005. You got it from Charity Hospital, a decrepit hulk in the middle of town, and it wasn't set up to keep you healthy. You showed up when you needed care right away, and you never got turned away. "My mama was born there," he said fondly. The hurricane ended that era in a day, ruining what was left of Charity and thrashing the city's already-frayed medical safety net. The trauma is still fresh, and the city's health care system is still a work in progress.