National Museum of Nuclear Science & History
D. S. Ewing worked for the Tennessee Eastman Corporation at the Y-12 Plant.
Messick worked in the 200 West Area at Hanford during the Manhattan Project.
Gilbert Plass was a Canadian physicist. Plass was born in 1922 in Toronto. He received a B.S. in physics from Harvard University before being hired to work on the Manhattan Project at the Chicago Met Lab, where he worked as an associate physicist.
