Seven patients at UCLA’s Ronald Reagan Medical Center have been infected with a drug-resistant superbug called CRE. Two of them have died. UCLA is reaching out to another 179 patients who were treated with the same contaminated equipment. Meanwhile, estimates for how many people die as a result of medical errors made by hospitals range from about 100,000 to 400,000 a year. At the higher end of those numbers, medical errors would be the third leading cause of death in America, behind heart disease and cancer. What goes into hospital safety ratings, and why did the Ronald Reagan Center only score a C in a recent ranking?