KFF Health News is examining the impact of national health care policy changes on uninsured people and their communities. Doctors, hospitals, and clinics that make up the health care safety net could lose so much money they must close their doors, some of them warn. “Uninsured patients stress the health care system.”Starr County shows how this dynamic unfolds. Her sister died at age 45 because she couldn’t afford health insurance to treat her heart disease and diabetes. SARA ROSENBAUM: You can’t disinsure this many people and not have, in many communities, just a collapse of the health care system.