On July 16, 1945, at 5:29:45 a.m., a light “brighter than a thousand suns,” filled the valley. As the now familiar mushroom cloud rose in to the sky, Oppenheimer quoted from Hindu scripture, the Bhagavad-gita, “Now I am become death, the destroyer of worlds.” The world had entered the nuclear age.
Immediately after the test a Sherman M-4 tank, equipped with its own air supply, and lined with two inches of lead went out to explore the site. The lead lining added 12 tons to the tank’s weight, but was necessary to protect its occupants from the radiation levels at ground zero. The tank’s passengers found that the 100 foot steel tower had virtually disappeared, with only the metal and concrete stumps of its four legs remaining. Surrounding ground zero was a crater almost 2,400 feet across and about ten feet deep in places. Desert sand around the tower had been fused by the intense heat of the blast into a jade colored glass, now known as Trinitite.