John Shannon Coogan was born on September 29, 1928, in North Hampton, Massachusetts. John married Betty Jean on August 16, 1952, and they had two children: John III and Sharon.

Coogan was enlisted in the United States Marine Corps.

Coogan attended the University of New Mexico.

Coogan is affiliated with the Nevada Test Site as part of Reynolds Electrical & Engineering Co (REECO); USPAS; and Environmental Protection Agency (EPA).

Layton James O'Neill was born on November 30, 1927, in Glendive, Montana. Layton married Melva Jean in October of 1976, and they had six children: Marilyn, Colleen, Michael, Jenny, Dennis, and Amy.

O'Neill was employed as a health physicist with Application Engineering Company (AEC) in affiliation with the Nevada Test Site. O'Neill also worked for Environmental Restoration and Waste Management (ERWM) and for the Department of Energy (DOE). O'Neill retired in 1994.

George Simmons was born on July 26, 1937 in Roxton, Texas. He studied at Texas Southern University and at the University of Texas. He moved to Las Vegas, Nevada in 1963 with his wife Eva. George Simmons designed homes for Sproul Homes in the 1960s, then was hired by the engineering firm Holmes and Narver. He worked for Holmes and Narver on a Department of Defense contract at the Nevada Test Site and in downtown Las Vegas. He is active in community groups and Black Golfers Association. Simmons retired in December of 2013.