Isidor Isaac Rabi attended the Trinity test in July 1945. The scientists working on Trinity set up a betting pool on the yield of the test, with predictions ranging from total dud to 45 kilotons of TNT equivalent (kt). Rabi arrived late and found the only entry left was for 18 kilotons, which he purchased. Wearing welding goggles, he waited for the result with Ramsey and Enrico Fermi. The blast was rated at 18.6 kilotons, and Rabi won the pool.
About 800 yards south of ground zero at Trinity Site, construction engineers built a heavy-duty 20-foot wooden platform. It had to be sturdy because they then stacked 108 tons of TNT on top of it. Then, on May 7, 1945, well before dawn, the neatly stacked boxes of TNT were detonated.