The University of Chicago Medical Center on the city's South Side is seen Friday, Nov. 16, 2007. It is one of three hospitals federal officials said Thursday, Nov. 15,  they are investigating about what they knew and told four organ transplant patients about a high-risk donor who infected them with HIV and hepatitis. AP Photo logo AP Photo 24 months ago

The University of Chicago Medical Center on the city's South Side is seen Friday, Nov. 16, 2007. It is one of three hospitals federal officials said Thursday, Nov. 15, they are investigating about what they knew and told four organ transplant patients about a high-risk donor who infected them with HIV and hepatitis.