The day the sun rose twice: Hiroshima and the first horrifying time an atomic bomb was dropped

By the mid-1940s, the globe was engulfed in the unprecedented violence and upheaval of the Second World War.

Despite victories on both the European and Pacific fronts, Allied forces were grappling with the prospect of a prolonged and costly invasion of mainland Japan.

The Japanese, with a deeply ingrained cultural code of honor, were expected to resist fiercely, drawing the war out and leading to an estimated hundreds of thousands, if not millions, of casualties.

Meanwhile, unbeknownst to the world, a secret project was underway that sought to harness the raw and terrifying power of the atom.

The Manhattan Project, initiated in 1939 and ramped up significantly in 1942, was a concerted effort by the United States, aided by the United Kingdom and Canada, to develop the first atomic weapons.

This monumental undertaking brought together some of the greatest scientific minds of the time, including Robert Oppenheimer, Enrico Fermi, and Niels Bohr.

They worked in secret facilities across the U.S., with the primary location in Los Alamos, New Mexico.

This scientific and military endeavor was largely spurred by fears that Nazi Germany was developing its own nuclear weaponry.

However, by the time the first successful nuclear test - known as the "Trinity" test - was conducted on July 16, 1945, Germany had already surrendered, leaving Japan as the remaining Axis power.

The atomic bomb was a terrifyingly powerful weapon, the likes of which the world had never seen.

The bomb dropped on Hiroshima, known as "Little Boy," was a uranium-based device that relied on nuclear fission to unleash an explosion equivalent to approximately 15 kilotons of TNT.

The power of this single bomb was greater than all the explosives used in the entirety of World War I.

The decision to use atomic weaponry was a complex one, influenced by an array of strategic, political, and moral factors.

When President Harry S. Truman took office after the death of Franklin D. Roosevelt in April 1945, World War II was still raging.

Truman was initially unaware of the Manhattan Project, but upon being briefed about this new and devastating weapon, he was confronted with a difficult decision.

The president and his advisors had to weigh the potential human cost against the perceived need to bring a swift end to the war.

One of the key elements factoring into the decision was the anticipated difficulty of a conventional invasion of Japan.

Allied intelligence suggested that Japan, despite being significantly weakened, was preparing for a fight to the bitter end.

A mainland invasion could have potentially resulted in a high number of casualties on both sides.

There were also geopolitical considerations at play, especially in relation to the Soviet Union.

Although the Allies had cooperated to defeat Nazi Germany, there were underlying tensions and the beginnings of the ideological rift that would lead to the Cold War.

Demonstrating the power of the atomic bomb could serve as a strong deterrent and a bargaining chip in the impending post-war negotiations.

Despite these reasons, the decision to use atomic bombs was not without controversy.

Some scientists who worked on the Manhattan Project, as well as a few military and political figures, voiced objections.

They argued the bomb was a weapon of mass destruction that should not be used or that Japan should be warned before its use. However, these views did not sway the ultimate decision.

On July 26, 1945, the Potsdam Declaration was issued, calling for Japan's unconditional surrender and warning of "prompt and utter destruction" without specifying the nature of the new weapon. Japan's leadership did not accept this ultimatum.

In early August 1945, the decision was made. The target was Hiroshima. The course of history was about to be irrevocably changed by the immense power contained within a single bomb. 

The early morning hours of August 6, 1945, began like any other day in Hiroshima. Nestled around seven river deltas on the coast of Japan's Honshu Island, Hiroshima was a bustling city, a key military and strategic target due to its military installations, industrial activity, and sizeable population.

Little did its inhabitants know that their city had been chosen as the first target of a weapon with unprecedented destructive capacity.

At 2:45 a.m., a B-29 bomber named the "Enola Gay" took off from Tinian, a North Pacific island in the Marianas, 1,500 miles south of Japan.

Piloted by Colonel Paul W. Tibbets Jr., who had named the plane after his mother, Enola Gay Tibbets, the aircraft carried a crew of twelve men and a single, uranium-235 bomb codenamed "Little Boy."

At 8:15 a.m. local time, the bomb bay doors of the Enola Gay opened, and "Little Boy" was released into the clear morning sky.

Forty-three seconds later, at an altitude of approximately 1,890 feet, the bomb detonated. The impact of the explosion was immediate and devastating.

A brilliant flash of light, many times brighter than the sun, filled the sky, followed by a shockwave that leveled buildings and set the city ablaze.

A fireball with a temperature hotter than the sun's surface incinerated everything within a one-mile radius of ground zero, the point directly below the detonation.

The bomb killed and injured thousands instantaneously, many of whom were civilians, while the resulting fires raged across the city, causing further damage and death.

From the air, the crew of the Enola Gay witnessed the mushroom cloud billowing up into the sky, a chilling testament to the devastation they had just unleashed.

The city of Hiroshima, a bustling urban center just moments before, lay in ruins, blanketed by the eerie silence of destruction.

The immediate impact of the atomic bomb on Hiroshima was nothing short of apocalyptic.

The detonation, which occurred approximately 600 meters above the city, unleashed a force equivalent to 15,000 tons of TNT, instantly reducing a bustling metropolis to a smoldering ruin.

The intense heat and pressure of the blast wave incinerated everything in its path within a one-mile radius of ground zero.

The extreme temperatures, estimated to have exceeded 3000 to 4000 degrees Celsius, caused severe burns to exposed skin, even at significant distances from the epicenter.

People near the hypocenter were vaporized instantly, their bodies reduced to mere shadows imprinted on concrete and stone.

The blast also generated a shockwave that traveled at the speed of sound, obliterating buildings and other structures.

Roughly 70,000 of Hiroshima's 76,000 buildings were damaged or destroyed. Fires sparked by the heat and destruction quickly spread, fueled by ruptured gas lines and flammable materials, causing a firestorm that ravaged the city and further impeded rescue efforts.

An estimated 70,000 to 80,000 people, approximately 30% of Hiroshima's population, were killed immediately or within the first day.

This included both military personnel and a significant number of civilians. The exact number is challenging to ascertain due to the complete devastation of civil records and the chaos following the explosion.

Those who survived the initial blast were left to grapple with a nightmarish landscape of collapsed buildings, raging fires, and the horrific injuries of those around them.

Many were severely injured, suffering from burns, wounds from flying debris, and the effects of intense radiation exposure.

Radiation sickness began to take hold in the hours following the detonation, resulting in symptoms such as nausea, vomiting, diarrhea, fatigue, fever, and a significant drop in white blood cells.

These initial symptoms were followed by a period of apparent recovery, before additional, more severe symptoms began to appear.

The physical and psychological trauma inflicted on the survivors, known as Hibakusha, was immense.

Amid the horror and destruction, these individuals displayed immense resilience as they navigated the aftermath of the bombing, working to rescue others, find loved ones, and simply survive in a city that had become unrecognizable overnight.

Three days after the devastation of Hiroshima, on August 9, 1945, a second atomic bomb was dropped on Nagasaki.

Originally, the city of Kokura was the primary target, but due to visibility issues, the B-29 bomber Bockscar diverted to its secondary target, Nagasaki.

The bomb, nicknamed "Fat Man," was a plutonium implosion-type device, even more potent than the uranium bomb "Little Boy" dropped on Hiroshima.

The hilly terrain of Nagasaki and the off-target detonation resulted in a somewhat reduced radius of total destruction, but the death toll and the devastation were still enormous.

Approximately 40,000 people were killed instantly, with thousands more injured. Like Hiroshima, Nagasaki was transformed in a matter of seconds, its population subjected to the same horrors of heat, blast, and radiation.

In the face of this unprecedented devastation, and with the Soviet Union declaring war on Japan on August 8, Japan's leaders found themselves in an untenable position.

After several days of intense debate within the government and the imperial household, Emperor Hirohito intervened, a highly unusual act, given the constitutional limits on the emperor's power.

On August 15, 1945, Hirohito announced Japan's surrender in a radio broadcast, an unprecedented event and the first time the Japanese public had heard their emperor's voice.

Known as the Jewel Voice Broadcast, Hirohito's speech referred to the devastating power of "a new and most cruel bomb" as a significant reason for Japan's surrender.

While the emperor's announcement signaled the end of World War II, the reality of surrender was fraught with tension.

Some military factions attempted a coup in an effort to prevent the surrender, reflecting the deeply ingrained ethos of fighting to the end.

The coup failed, and the formal surrender document was signed aboard the USS Missouri on September 2, 1945.

The first use of nuclear weapons in warfare remains the subject of intense debate and controversy.

The primary justification offered by those in favor of the bombings was that they hastened the end of World War II, saving countless lives that would have been lost in a protracted Allied invasion of Japan.

Critics, however, have questioned the necessity and morality of using such devastating weapons, particularly against cities with large civilian populations.

Some argue that Japan was already on the brink of surrender and that other factors, like the Soviet Union's declaration of war against Japan, were equally instrumental in Japan's decision to surrender.

Controversy also surrounds the lack of explicit warning given to the residents of Hiroshima and Nagasaki about the nature of the atomic bomb, although leaflets warning of severe bombings were dropped on various Japanese cities.

Moreover, the selection of these particular cities, both significant civilian centers, has been the subject of scrutiny.

These debates have influenced the way these events are remembered and interpreted in public memory and education, both in Japan and worldwide.

In the United States, history textbooks often present the bombings as a necessary evil to end the war quickly.

In contrast, Japanese accounts focus more on the victims' experiences and the peace movement that emerged from the ashes.

The bombings catalyzed a significant push for scientific and technological progress.

The sheer destructiveness of the atomic bombs sparked an arms race during the Cold War, leading to the development of more potent thermonuclear weapons.

Paradoxically, the knowledge gained from the destructive application of nuclear energy also paved the way for peaceful uses, including nuclear power generation and advancements in medicine.

Out of the horrors of Hiroshima and Nagasaki, a robust global movement for peace and nuclear disarmament was born.

Annual commemorations at Hiroshima and Nagasaki serve as a poignant reminder of the bombings' human cost and a call for a world free of nuclear weapons.

The accounts of the Hibakusha, the survivors of the bombings, have played a vital role in humanizing the abstract concept of nuclear war and highlighting its catastrophic consequences.