Now I am become death, the destroyer of worlds.
At 4:45 am a crucial weather report came in favorably, and at 5:10 am the twenty-minute countdown began. Most top-level scientists and military officers were observing from a base camp ten miles southwest of the test tower. Many other observers were around twenty miles away, and some others were scattered at different distances, some in more informal situations (physicist Richard Feynman claimed to be the only person to see the explosion without the dark glasses provided, relying on a truck windshield to screen out harmful ultraviolet wavelengths). The final countdown was read by physicist Samuel K. Allison.
At 05:29:45 local time (Mountain War Time), the device exploded with an energy equivalent to around 20 kilotons of TNT. It left a crater of radioactive glass in the desert 10 feet deep and 1,100 feet wide. At the time of detonation, the surrounding mountains were illuminated "brighter than daytime" for one to two seconds, and the heat was reported as "being as hot as an oven" at the base camp. The observed colors of the illumination ranged from purple to green and eventually to white. The roar of the shock wave took 40 seconds to reach the observers. The shock wave was felt over 100 miles away, and the mushroom cloud reached 7.5 miles in height. After the initial euphoria of witnessing the explosion had passed, test director Kenneth Bainbridge commented to Los Alamos director J. Robert Oppenheimer, "Now we are all sons of bitches."Oppenheimer later stated that while watching the test he was reminded of a line from the Hindu scripture the Bhagavad Gita:
Now I am become Death, the destroyer of worlds.