Leslie Groves

Lieutenant General Leslie Richard Groves Jr. (August 17, 1896 – July 13, 1970) was a United States Army Corps of Engineers officer. He helped construct the Pentagon and directed the Manhattan Project, which helped create the atomic bomb during World War II.
Groves had a heart attack on July 13, 1970. He died a few hours later at the Walter Reed Army Medical Center in Washington, D.C. at age 73.