Spc. Richard Leroy McKinley's grave in Arlington Cemetery is a unique and somber site, marking the first fatal nuclear accident in the United States. McKinley, born on December 2, 1933, enlisted in the United States Air Force in 1951 and later served at the National Reactor Testing Station in Idaho. On January 3, 1961, a steam explosion in the Stationary Low-Power Reactor Number One (SL-1) resulted in the deaths of two other servicemen, while McKinley survived the initial blast but succumbed to his injuries shortly thereafter at the age of 27. His burial site is the only radioactive grave in the cemetery, secured in a double lead-lined casket and surrounded by a 10-foot concrete vault. Visitors to his grave are reminded of the grave danger posed by nuclear energy, as his cemetery file warns that his body is contaminated with long-life radioactive isotopes. The tragic circumstances of his death left behind a grieving family, including his wife and two children, who had to witness his funeral from a distance due to safety protocols.