U.S. Senator Daniel Inouye died Monday of respiratory complications at a Washington-area hospital, his office said. Inouye (Democrat from Hawaii) was 88 years old and was the longest serving member of the Senate at 50 years of service. He was also president pro tempore of the Senate - third in the line of presidential succession. Senate Majority Leader Harry Reid (Democrat from Nevada) announced Inouye's death on the floor of the Senate.