The D.C. Council voted Tuesday to establish a nonprofit corporation to seize control of United Medical Center at a foreclosure auction next week, even though the District's chief financial officer warned members that the city might not be able to afford it. After months of wrangling between the city and Specialty Hospitals of America, the hospital's owner, Attorney General Peter Nickles plans to auction the Southeast Washington hospital on the steps of the John A. Wilson Building on July 9.