Question: What was the first of these types in which was supervised by Walter Zinn of the Manhattan Project?
Sentence (from "Chicago Pile-1"): The first human-made self-sustaining nuclear chain reaction was initiated in CP-1 on 2 December 1942, under the supervision of Enrico Fermi, who described the apparatus as "a crude pile of black bricks and wooden timbers".
Relevant evidence: No