Riddle Memorial Hospital President and CEO Dan Kennedy is retiring at the end of the year after 29 years with the Delaware County, PA, hospital. Kennedy joined Riddle in 1979 and was appointed president and CEO of Riddle in 2001. No decision on his successor has been made. Donald C. Arthur, MD, the CMO of Main Line Health, will serve as interim president of Riddle while a search for a new CEO takes place.