Three unexplained deaths have prompted the Minnesota Health Department to ask all hospitals in the state to suspend elective knee surgery. Three men died earlier this month of septic shock within days of undergoing the same type of knee surgery. Two of the men had surgery at St. Cloud Hospital, and the third at a hospital 70 miles away in Alexandria. The Health Department is asking the Center for Disease Control in Atlanta to assist in the invesitgation. State epidemiologist Doctor Harry Hull says the case is unprecedented: