Sixty-six years ago this week, US policymakers and President Truman made fateful decisions that meant the use of two atomic bombs against Japanese cities was almost inevitable—virtually unstoppable. Then film footage and other evidence of the true effects of the bomb were suppressed for decades. We’ve been living with the nuclear after-effects ever since, from Hiroshima to Fukushima.

Starting Monday, and related to publication of my new book and e-book Atomic Cover-up, on that film’s suppression, I began offering a daily record of what transpired leading up the bombing of Hiroshima and Nagasaki in 1945. (For more, including video, see my personal blog.)

On this day in 1945:

—Secretary of War Henry L. Stimson, now back at the Pentagon, cabled President Truman, still in Potsdam, that he had drafted a statement for the president that would follow the first use of the new weapon—and Truman must urgently review it because the bomb could be used as early as August 1. Stimson sent one of his aides to Germany with two copies of the statement. The Top Secret, six-page typed statement opened: “__ hours ago an American airplane dropped one bomb on ____ and destroyed its usefulness to the enemy. That bomb has more power than 20,000 tons of TNT…. It is an atomic bomb. It is a harnessing of the basic power of the universe.”

In his diary, Stimson noted that at the end he had put more “pep” into the document to make it more “dramatic.” Later, as we will see, the claim that Hiroshima was merely “a military base” was added later to the draft.

—After scientists sifted more data from the July 16 Trinity test of the first weapon, Gen. Leslie R. Groves, military head of the Manhattan Project provided Gen. George Marshall, our top commander, with more detail on the destructive power of atomic weapons. Amazingly, despite the new evidence, Groves recommended that troops could move into the “immediate explosion area” within a half hour,” although this would not be an issue in the first use against Japan. Groves also provided the schedule for the delivery of the weapons: the components of the gun-type bomb to be used on Hiroshima had arrived on Tinian, while the parts of the second plutonium weapon to be dropped were leaving San Francisco. By the end of November more than ten weapons would be available, in the event the war had continued.

—Groves faced a new problem, however. Gen. “Tooey” Spaatz on Guam urgently cabled that sources suggested that there was an Allied prisoner of war camp in Nagasaki just a mile north of the center of the city. Should it remain on the target list?” Groves, who had already dropped Kyoto from the list after Stimson had protested (it was just too beautiful and culturally important), refused to shift. In another cable Spaatz revealed that there were no POW camps in Hiroshima, or so they believed. This firmed up Groves’s position that Hiroshima should “be given top priority,” weather permitting. As it turned out, POWs died in both cities from the bombing.

—Truman’s diary today had no mention of the bomb but he did write: “If Stalin should suddenly cash in it would end the original Big Three. First Roosevelt by death, then Churchill by political failure and then Stalin. I am wondering what would happen to Russia and central Europe if Joe suddenly passed out. If some demagogue on horse back gained control of the efficient Russian military machine he could play havoc with European peace for a while.”

Greg Mitchell’s new book (also out as an e-book) is Atomic Cover-Up: Two US Soldiers, Hiroshima & Nagasaki, and The Greatest Movie Never Made. He also co-authored, with Robert Jay Lifton, Hiroshima in America.