Heart surgeon Dr. Michael DeBakey (C), pictured on April 23, 2008 with U.S. President George W. Bush (L) and Speaker of the House Nancy Pelosi (D-CA) after he received a Congressional Gold Medal in Washington, died at the age of 99 of natural causes in Houston on July 11, 2008. DeBakey is credited with starting the Mobile Army Surgical Hospital (M.A.S.H.) unit and perfecting heart transplant procedures. (UPI Photo/Roger L. Wollenberg)