The design for the "Superfortress," as it was called, had been laid down as a follow on to the B-17 "Flying Fortress" in the 1930's .  It had the range to fly a mission from North America to Europe.  It had originally been sent to China, but supply lines requiring a flight over the "hump" of Burma made it almost useless. It had growing pains: a complex aircraft placed into production too soon, and during war.

    Now LeMay had a few months to prove that his idea would work.  He had a maturing weapon and a major command to place it into action.  But high level attacks, using High Explosives (H-E) did little to cripple the Empire.  B-29 loses rose at an alarming rate.  There had to be a better way.

    For LeMay there was:  In 1943 an architect, who had spent 16 years in Japan, built an exact replica of a Japanese community (down to the books on the selves and the straw mats on the floors) at the Dugway proving grounds in Utah. Then the army tried different ways of destroying it. The solution was to be called the M69 Incendiary. It was a small bomb.  It made a very Hot fire. A B-29 could carry hundreds of them.

    On the night of March 9, 1945, three hundred twenty five of the Big bombers lifted off their bases in the Marianas. This night they would make their bomb run at between 5,000 and 8,000 ft, rather then the 25,000+ft they usually flew.  They would carry only incendiary and their target was listed as "Urban Area."   Tokyo.

    Sixteen square miles of Tokyo had been burned; 83,000 people had died; 267,171 buildings were destroyed.  In his book, Wings of Fire, Edward Jablonski says, "Tokyo did not suffer a firestorm in the manner of Hamburg or Dresden; not the whirling, sucking inferno of those German cities, but a massive plunging fire-comparable to a moving prairie fire-sweeping all before it.  The heat rose to more then 1800(f).  If this heat could fling about a 74,500lb aircraft as if it were a leaf in the wind, only the imagination can conceive of what it did to the Japanese trapped in the immolation.  No city on earth -- not Warsaw, or Rotterdam, or London, or Hamburg, or Berlin, not even Dresden (or to come: Hiroshima and Nagasaki) -- suffered so great a disaster, so much agony, so much human despair and loss of life."

    For the Americans B-29 loses were below 4%; very acceptable.  And this was just the beginning. Although one of the worst of the fire bomb rades in loss of life, it wasn't as proficient as LeMay's men were to become before the end of the war.  Cities burned.  Here's a partial list of Japanese cities and their American counterparts, along with the percent destruction of the Bombings. (does not include damage done by Other Services.)
 

    In all, 69 cities were attacked.  Before it was over, LeMay was running out of Military (or anything that could even vaguely be called military) targets.  LeMay had reason to believe that he was winning the war.  As a bit of psychological warfare the Americans WARNED the Japanese they were coming.