paragraph_text: ``Little Boy ''was the codename for the atomic bomb dropped on the Japanese city of Hiroshima on 6 August 1945 during World War II by the Boeing B - 29 Superfortress Enola Gay, piloted by Colonel Paul W. Tibbets, Jr., commander of the 509th Composite Group of the United States Army Air Forces. It was the first atomic bomb to be used in warfare. The Hiroshima bombing was the second artificial nuclear explosion in history, after the Trinity test, and the first uranium - based detonation. It exploded with an energy of approximately 15 kilotons of TNT (63 TJ). The bomb caused significant destruction to the city of Hiroshima and its occupants.

paragraph_text: The staff officer went to the airport and took off for the southwest. After flying for about three hours, while still nearly 160 km (100 mi) from Hiroshima, he and his pilot saw a great cloud of smoke from the bomb. After circling the city in order to survey the damage they landed south of the city, where the staff officer, after reporting to Tokyo, began to organize relief measures. Tokyo's first indication that the city had been destroyed by a new type of bomb came from President Truman's announcement of the strike, sixteen hours later.

paragraph_text: On 6 August 1945, the U.S. dropped an atomic bomb on the Japanese city of Hiroshima in the first nuclear attack in history. In a press release issued after the atomic bombing of Hiroshima, Truman warned Japan to surrender or "...expect a rain of ruin from the air, the like of which has never been seen on this earth." Three days later, on 9 August, the U.S. dropped another atomic bomb on Nagasaki, the last nuclear attack in history. More than 140,000–240,000 people died as a direct result of these two bombings. The necessity of the atomic bombings has long been debated, with detractors claiming that a naval blockade and aerial bombing campaign had already made invasion, hence the atomic bomb, unnecessary. However, other scholars have argued that the bombings shocked the Japanese government into surrender, with Emperor finally indicating his wish to stop the war. Another argument in favor of the atomic bombs is that they helped avoid Operation Downfall, or a prolonged blockade and bombing campaign, any of which would have exacted much higher casualties among Japanese civilians. Historian Richard B. Frank wrote that a Soviet invasion of Japan was never likely because they had insufficient naval capability to mount an amphibious invasion of Hokkaidō.

paragraph_text: The Davidka (, ""Little David"") was a homemade Israeli mortar used in Safed and Jerusalem during the early stages of the 1948 1947–1949 Palestine war. Its bombs were reported to be extremely loud, but very inaccurate and otherwise of little value beyond terrifying opponents; they proved particularly useful in scaring away both Arab soldiers and civilians. It is nominally classified as a 3-inch (76.2 mm) mortar, although the bomb was considerably larger.

paragraph_text: During the early years of the Cold War from 1946 to 1958, the United States tested 67 nuclear weapons at its Pacific Proving Grounds located in the Marshall Islands, including the largest atmospheric nuclear test ever conducted by the U.S., code named Castle Bravo. "The bombs had a total yield of 108,496 kilotons, over 7,200 times more powerful than the atomic weapons used during World War II." With the 1952 test of the first U.S. hydrogen bomb, code named "Ivy Mike," the island of Elugelab in the Enewetak atoll was destroyed. In 1956, the United States Atomic Energy Commission regarded the Marshall Islands as "by far the most contaminated place in the world."

paragraph_text: In 1945, the sinking of Indianapolis led to the greatest single loss of life at sea, from a single ship, in the history of the US Navy. The ship had just finished a high - speed trip to United States Air Force Base at Tinian, to deliver parts of the first atomic bomb ever used in combat (the United States' Little Boy atomic bomb), and was on training duty. At 0015 on 30 July 1945 the ship was torpedoed by the Imperial Japanese Navy submarine I - 58. The ship, on her way to the Philippines, sank in 12 minutes. Of 1,196 crewmen aboard, approximately 300 went down with the ship. The remaining 900 faced exposure, dehydration, saltwater poisoning, and shark attacks while floating with few lifeboats and almost no food or water. The Navy learned of the sinking when survivors were spotted four days later by the crew of a PV - 1 Ventura on routine patrol. Only 317 survived.

paragraph_text: On April 15, 2013, two Chechen Islamist brothers exploded two bombs near the finish line of the Boston Marathon, killing three people and injuring roughly 264.

paragraph_text: The March 2012 Damascus bombings were two large car bombs that exploded in front of the air intelligence and criminal security headquarters in the Syrian capital of Damascus. At least 27 people were reported killed and over a 140 injured in the fourth major bombing since the beginning of the uprising and the second in the city. As in previous cases, the opposition blamed the government for orchestrating attacks, while the government placed the blame on terrorists and foreign groups.

paragraph_text: The Droppin Well bombing or Ballykelly bombing occurred on 6 December 1982, when the Irish National Liberation Army (INLA) exploded a time bomb at a disco in Ballykelly, Northern Ireland. The disco, known as the Droppin Well, was targeted because it was frequented by British Army soldiers from nearby Shackleton Barracks. The bomb killed eleven soldiers and six civilians; 30 people were injured, this made it the most deadly attack during the INLA's paramilitary campaign and the most deadly attack during The Troubles carried out in County Londonderry.

paragraph_text: By August 1945, the Allies' Manhattan Project had produced two types of atomic bomb, and the 509th Composite Group of the United States Army Air Forces (USAAF) was equipped with the specialized Silverplate version of the Boeing B - 29 Superfortress that could deliver them from Tinian in the Mariana Islands. Orders for atomic bombs to be used on four Japanese cities were issued on July 25. On August 6, one of its B - 29s dropped a Little Boy uranium gun - type bomb on Hiroshima. Three days later, on August 9, a Fat Man plutonium implosion - type bomb was dropped by another B - 29 on Nagasaki. The bombs immediately devastated their targets. Over the next two to four months, the acute effects of the atomic bombings killed 90,000 -- 146,000 people in Hiroshima and 39,000 -- 80,000 people in Nagasaki; roughly half of the deaths in each city occurred on the first day. Large numbers of people continued to die from the effects of burns, radiation sickness, and other injuries, compounded by illness and malnutrition, for many months afterward. In both cities, most of the dead were civilians, although Hiroshima had a sizable military garrison.

paragraph_text: The June 2011 Peshawar bombings occurred on 12 June 2011 in Peshawar, Khyber Pakhtunkhwa, Pakistan. At least 34 people were killed, and more than 90 were injured, when two bombs exploded in a market around midnight. The first bomb went off around 11:50 p.m. local time in Khyber market area, which is a commercial and residential area, and injured 3 people. After a crowd gathered in the area, a teen-aged suicide bomber on a motorcycle set off a second explosion, killing many people on the spot. About of explosives were used in the second blast according to officials.

paragraph_text: 6998150000000000000 ♠ 1.5 × 10 -- 6998200000000000000 ♠ 2 × 10 17.4 -- 23.2 GWh The Little Boy atomic bomb dropped on Hiroshima on August 6, 1945, exploded with an energy of about 15 kilotons of TNT (63 TJ), and the Fat Man atomic bomb dropped on Nagasaki on August 9, 1945, exploded with an energy of about 20 kilotons of TNT (84 TJ). The modern nuclear weapons in the United States arsenal range in yield from 0.3 kt (1.3 TJ) to 1.2 Mt (5.0 PJ) equivalent, for the B83 strategic bomb.

paragraph_text: The first bombs delivered to their targets by air were launched on unmanned balloons, carrying a single bomb, by the Austrians against Venice in 1849, during the First Italian War of Independence.

paragraph_text: Behind the scenes, the Soviet government was working on building its own atomic weapons. During the war, Soviet efforts had been limited by a lack of uranium but new supplies in Eastern Europe were found and provided a steady supply while the Soviets developed a domestic source. While American experts had predicted that the Soviet Union would not have nuclear weapons until the mid-1950s, the first Soviet bomb was detonated on August 29, 1949, shocking the entire world. The bomb, named ``First Lightning ''by the West, was more or less a copy of`` Fat Man'', one of the bombs the United States had dropped on Japan in 1945.

paragraph_text: By August 1945, the Allies' Manhattan Project had produced two types of atomic bombs, and the 509th Composite Group of the United States Army Air Forces (USAAF) was equipped with the specialized Silverplate version of the Boeing B - 29 Superfortress that could deliver them from Tinian in the Mariana Islands. Orders for atomic bombs to be used on four Japanese cities were issued on July 25. On August 6, the U.S. dropped a uranium gun - type (Little Boy) bomb on Hiroshima, and American President Harry S. Truman called for Japan's surrender, warning it to ``expect a rain of ruin from the air, the like of which has never been seen on this earth. ''Three days later, on August 9, a plutonium implosion - type (Fat Man) bomb was dropped on Nagasaki. Within the first two to four months following the bombings, the acute effects of the atomic bombings had killed 90,000 -- 146,000 people in Hiroshima and 39,000 -- 80,000 in Nagasaki; roughly half of the deaths in each city occurred on the first day. During the following months, large numbers died from the effect of burns, radiation sickness, and other injuries, compounded by illness and malnutrition. In both cities, most of the dead were civilians, although Hiroshima had a sizable military garrison.

paragraph_text: The 25 August 2003 Mumbai bombings were twin car bombings in the Indian city of Mumbai that killed 54, and injured 244 people. One of the bomb explosions took place at the Gateway of India, which is a major tourist attraction. The other bomb went off in a jewellery market Zaveri Bazaar near the Mumba Devi temple in central Mumbai. Both the bombs were planted in parked taxis and exploded during the lunch hour. No group initially claimed responsibility for the attack, but Kashmir rebel group and Pakistan-based Lashkar-e-Toiba was blamed for it.

paragraph_text: The Enola Gay (/ ɪˈnoʊlə ˈɡeɪ /) is a Boeing B - 29 Superfortress bomber, named for Enola Gay Tibbets, the mother of the pilot, Colonel Paul Tibbets, who selected the aircraft while it was still on the assembly line. On 6 August 1945, during the final stages of World War II, it became the first aircraft to drop an atomic bomb. The bomb, code - named ``Little Boy '', was targeted at the city of Hiroshima, Japan, and caused unprecedented destruction. Enola Gay participated in the second atomic attack as the weather reconnaissance aircraft for the primary target of Kokura. Clouds and drifting smoke resulted in a secondary target, Nagasaki, being bombed instead.

paragraph_text: The war in Europe concluded with an invasion of Germany by the Western Allies and the Soviet Union, culminating in the capture of Berlin by Soviet troops, the suicide of Adolf Hitler and the subsequent German unconditional surrender on 8 May 1945. Following the Potsdam Declaration by the Allies on 26 July 1945 and the refusal of Japan to surrender under its terms, the United States dropped atomic bombs on the Japanese cities of Hiroshima and Nagasaki on 6 and 9 August respectively. With an invasion of the Japanese archipelago imminent, the possibility of additional atomic bombings and the Soviet invasion of Manchuria, Japan formally surrendered on 2 September 1945. Thus ended the war in Asia, cementing the total victory of the Allies.

paragraph_text: During the later stages of World War II, the entire Cold War, and to a lesser extent afterwards, uranium-235 has been used as the fissile explosive material to produce nuclear weapons. Initially, two major types of fission bombs were built: a relatively simple device that uses uranium-235 and a more complicated mechanism that uses plutonium-239 derived from uranium-238. Later, a much more complicated and far more powerful type of fission/fusion bomb (thermonuclear weapon) was built, that uses a plutonium-based device to cause a mixture of tritium and deuterium to undergo nuclear fusion. Such bombs are jacketed in a non-fissile (unenriched) uranium case, and they derive more than half their power from the fission of this material by fast neutrons from the nuclear fusion process.

paragraph_text: In November 1945, Eisenhower returned to Washington to replace Marshall as Chief of Staff of the Army. His main role was rapid demobilization of millions of soldiers, a slow job that was delayed by lack of shipping. Eisenhower was convinced in 1946 that the Soviet Union did not want war and that friendly relations could be maintained; he strongly supported the new United Nations and favored its involvement in the control of atomic bombs. However, in formulating policies regarding the atomic bomb and relations with the Soviets, Truman was guided by the U.S. State Department and ignored Eisenhower and the Pentagon. Indeed, Eisenhower had opposed the use of the atomic bomb against the Japanese, writing, "First, the Japanese were ready to surrender and it wasn't necessary to hit them with that awful thing. Second, I hated to see our country be the first to use such a weapon." Initially, Eisenhower was characterized by hopes for cooperation with the Soviets. He even visited Warsaw in 1945. Invited by Bolesław Bierut and decorated with the highest military decoration, he was shocked by the scale of destruction in the city. However, by mid-1947, as East–West tensions over economic recovery in Germany and the Greek Civil War escalated, Eisenhower gave up and agreed with a containment policy to stop Soviet expansion.

Question: Who was the US president when the city where the first atomic bomb used in war exploded was bombed?
Answer: President Truman