The atomic bombs dropped on Japan had massive human costs

The death toll of the atomic bombings in Japan remains disputed, with estimates ranging from 110,000 to 210,000.

On August 6, 1945, the Enola Gay dropped the first atomic bomb used in warfare on Hiroshima, Japan, killing at least 80,000 people instantly.

Nine eyewitness accounts of Hiroshima and Nagasaki survivors

Japan's Hiroshima and Nagasaki became the first cities in history to be hit with nuclear weapons, where tens of thousands of civilians were killed nearly instantly. Hundreds of thousands of people who survived the bombings—referred to as hibakusha—dealt with wounds, radiation poisoning, and alienation from a society unable to process what had happened. This collection of accounts lets nine of those survivors speak, including one of the 165 survivors of both bombings.

Okinawa’s ferocity convinced the US atomic bombs was necessary

The brutal 82-day Battle of Okinawa—where US forces suffered nearly 50,000 casualties and Japanese military and civilians lost over 200,000 lives—clinched the grim reality that a full invasion of Japan would be even bloodier. This stark lesson directly shaped American decisions to deploy atomic weapons, aiming to avoid a potentially catastrophic ground war on the Japanese mainland.

A list of reasons against dropping the bomb on Japan

One of the perennial moral debates, the dropping of nuclear bombs on Japanese cities prompted strong, polarizing reactions at the time. This article breaks down one side of the argument: that the bomb was designed for defense, using it was illegal and racist, and that there were alternatives.

Cold War nuclear tests exposed thousands to atomic blasts

After World War II, nuclear powers conducted thousands of weapons tests. This video pairs archival footage with interviews of veterans who witnessed Pacific test explosions, capturing the scale, shock, and human experience of being near a nuclear detonation.

Nuclear weapons in WWII

This 14-minute interactive documentary broaches the subject of the human cost of nuclear warfare. Comparing the number of deaths during World War II with the projected deaths of a nuclear exchange, the video can be paused to delve deeper into individual statistics, historical tidbits, and more data that shows the terrible price humanity would pay.

John Hersey’s ‘Hiroshima’ focused on the stories of atomic bomb victims

The nonfiction book is considered one of the earliest pieces of New Journalism and an arresting case against nuclear warfare. Describing the pain, wounds and trauma of six ordinary citizens, “Hiroshima” played a powerful role in American perception of the war by focusing on its human toll.

A single bomb on the USS Arizona killed 1,177 crew members in seconds

When a Japanese armor-piercing bomb triggered the explosion of the USS Arizona’s forward magazine during the attack, the blast killed 1,177 crew members within moments—accounting for nearly half of all American deaths at Pearl Harbor.

Learn how Japan used the jet stream to launch attacks on US soil during World War II

In the final two years of the war, over 9,000 Fu-Go balloon bombs were launched from Japan, with about a thousand estimated to have reached North America. Six civilians killed by a Fu-Go bomb in Bly, Oregon, on May 5, 1945, became the only known deaths on American soil by enemy action during the war.

Oppenheimer reflected on the atomic bomb's legacy two decades later

In a 1965 CBS interview, J. Robert Oppenheimer discussed his role as Los Alamos director, expressing deeply mixed feelings about Hiroshima and Nagasaki and reflecting on how nuclear weapons had transformed the world since their first use.

The H-bomb is hundreds of times more powerful than the bomb dropped on Hiroshima

Unlike the atomic bombs dropped on Hiroshima, which relied on nuclear fission, the hydrogen bomb uses fusion to unleash vastly greater destructive power. Developed by both superpowers in the 1950s, it gave each the ability to destroy entire cities in seconds.

The Manhattan Project, the top-secret American program that built the world's first atomic bomb, cost $27B in today's dollars and reshaped global power.

The Manhattan Project was one of the most expensive undertakings of World War II

Building the first atomic weapons required hundreds of thousands of workers, vast secret facilities, and enormous spending. This 1998 study details the full cost of the Manhattan Project and compares it to other major US wartime expenditures.

The Chernobyl disaster released more radioactive material than the Hiroshima bomb.

What happened to Americans who were in Japan during Pearl Harbor?

When Japan bombed Pearl Harbor in December 1941, roughly 10,000 American civilians were stranded in Japanese-occupied territory. Tense diplomatic negotiations eventually secured two prisoner exchanges conducted via ship across 20,000 nautical miles to return nearly 3,000 Allied civilians, while Japanese Americans in North and South America were sent in the opposite direction, many to a country they had never called home.

The Pearl Harbor attack led to the mass internment of Japanese Americans

In the months after Pearl Harbor, the US forcibly removed and incarcerated about 120,000 Japanese Americans—two-thirds of them citizens. Driven by fear and racism, the policy is now recognized as a grave violation of civil rights.

Japan's attack on Pearl Harbor caused heavy losses but failed to cripple the US navy

Japan’s air assault sank or damaged 18 warships (including eight battleships) and destroyed 188 aircraft, killing 2,403 Americans, yet all three Pacific Fleet aircraft carriers were absent and survived, and vital infrastructure like oil depots and repair yards remained intact—preserving core US naval power and enabling a rapid recovery. Watch original reporting here.

The formal Japanese unconditional surrender that ended World War II took place on the deck of the USS Missouri in Tokyo Bay on Sept. 2, 1945.

Japan committed mass war crimes during its invasion of China

During the 1937 invasion, Japanese forces carried out systematic atrocities—including mass executions, rape, torture, forced labor, and chemical warfare. The Nanjing Massacre alone killed tens of thousands over a span of six weeks, with some estimates claiming 300,000.

Interviews from the Manhattan Project

This is an archive of interviews with people who worked on and were impacted by the Manhattan Project, the World War II-era effort that resulted in the atomic bomb. Listen to the "father of the atomic bomb," Julius Robert Oppenheimer, describe his daily routine during the project, which he reports officially started Dec. 6, 1941. This archive also includes interviews with survivors of the Hiroshima and Nagasaki bombings.

While both are nuclear weapons, atomic bombs release nuclear energy by splitting large atomic nuclei, whereas hydrogen bombs derive most of their energy from fusing heavy hydrogen isotopes.

The threat of nuclear annihilation reshaped global diplomacy

The first use of atomic weapons introduced the possibility of a war with no survivors. This article examines how nuclear fear shaped Cold War diplomacy and continues to influence international relations today.

The toxic dust from 9/11 sites still claims lives decades later

In the years after 9/11, nearly 17,000 first responders enrolled in health programs have reported cancers and respiratory diseases linked to Ground Zero exposure. More have died from related illnesses than were killed on the day itself.

View a timeline of the Chernobyl disaster

The 1986 Chernobyl meltdown, caused by a combination of poor safety design and human error, is the worst nuclear accident in history. At least three dozen people died in the direct aftermath, and experts believe thousands suffered premature cancer deaths from radiation exposure.

See how global nuclear arsenals surged—then shrank—by country since 1945

Worldwide nuclear stockpiles peaked at over 60,000 warheads in the mid‑1980s during the US-Soviet arms race. Today, about nine nations collectively maintain roughly 12,000 warheads, with Russia and the US still holding the majority.

Building the first atomic bomb required unprecedented coordination

Creating the first atomic bombs demanded breakthroughs in physics, engineering, and logistics—uniting elite scientists with tens of thousands of workers across the US. This in-depth history explains how the Manhattan Project overcame those challenges.

More than 500,000 people worked to contain Chernobyl's fallout, many with very little radiation protection.

Hiroshimaites are glass-like spheres of fallout debris found in Hiroshima, where conditions created by the atomic bomb forged a previously unknown metal alloy with a unique crystal structure.

A US project proposed a 10-gigaton nuclear bomb capable of global devastation

Planned in the early 1950s by US scientists, Project Sundial aimed to create a 10-gigaton thermonuclear bomb—hundreds of times more powerful than any weapon ever built. Had it been tested, it was expected to cause global environmental catastrophe.

Kurt Vonnegut's 'Cat's Cradle' was inspired by the bombing of Hiroshima

The writer fought in World War II and witnessed the firebombing of Dresden, which he recounted in 1969's satirical "Slaughterhouse Five." Six years earlier, though, he wrote about the bombing of Hiroshima in "Cat's Cradle," channeling some of the horror he witnessed in Dresden to write about the dropping of the atomic bomb. (Some users may experience a paywall.)

Exposure to ionizing radiation from nuclear accidents can damage DNA

The damage can increase the risks of cancer, cataracts, heart disease, and other illnesses based on exposure times and intensities. Contaminated food, water, air, or soil from near nuclear accidents can further prolong one's exposure.

The attacks prompted a quick jump in American public support for war

In a Gallup poll taken days after the attack, an extraordinary 97% of Americans approved Congress declaring war on Japan—reflecting overwhelming national unity in the wake of the strike.

How many people died in WWII?

Fallen.io, a short animated data-driven documentary about war and peace, explores the harrowing statistics of World War II and sizes up its numbers to other wars in history, including recent conflicts. Watch and click through this interactive documentary to learn more.

During the Cold War, a mid-air fire led to a nuclear bomber crash in Greenland that left a piece of a hydrogen bomb missing to this day.

Robert Oppenheimer became the face of the Manhattan Project and the atomic bomb

This feature explores Oppenheimer’s early life, the traits that made him central to the development of the atomic bomb, and how his later years were marked by tension between pride in his work and opposition to weapons of mass destruction.

The Manhattan Project operated at three key sites, each with a distinct role in building the first atomic bomb.

The story of the Manhattan Project's unused demon core

A 3-inch, 14-pound sphere of nuclear reactive plutonium-gallium was set to be delivered to the Pacific Theater in 1945 to become the third atomic bomb dropped over Japan. When Japan surrendered, it was returned to Los Alamos in New Mexico for experiment, where two scientists would die testing whether the core could reach criticality—where it would release intense energy—via the use of a dense reflector. Watch the story here.

The 1957 and 1968 influenza pandemics caused millions of deaths worldwide

The 1957 H2N2 pandemic spread from East Asia, killing more than 1M globally, while the 1968 H3N2 pandemic began in Hong Kong and caused a similar toll, with both strains rapidly moving across continents.

In 1962, the US detonated a nuclear weapon in space, which produced an electromagnetic pulse that disabled three low Earth orbit satellites and damaged electrical equipment in Hawaii.

Air pollution in war-torn Iran unleashes invisible toxic threats

Burning oil depots and bombed buildings are endangering the health of millions of people during the 2026 attacks. Heavy metals from munitions and other damaged materials are going airborne, but the exact health implications depends on dose, wind currents, and other factors including preexisting health conditions.

More than 58,000 American soldiers died in the Vietnam War

Fought to contain communism in Southeast Asia, the Vietnam War became one of the most costly and controversial Cold War conflicts. The US ultimately withdrew in 1973, and South Vietnam fell to communist forces two years later.

US intelligence failures contributed to the success of the Japanese attack

Despite breaking Japan’s diplomatic codes, US agencies failed to integrate warnings, successfully track Japan’s carriers, or even believe a Hawaii strike was possible (they also had not cracked Japan’s naval codes). Missed signals, ignored reports and poor coordination led to one of the worst intelligence failures in US history.

See what it was like to live in the United States during World War II

In America, life was transformed by total war: sixteen million service members left civilian life, while massive industrial production demanded labor. Women, minorities, and teens filled factories, fueling boomtown growth and breaking social barriers. Simultaneously, rationing, recycling drives, Victory Gardens, ration stamps, blackout drills, and war bond campaigns permeated daily routines.

From 1610 BCE to 2025 CE, at least 250 of the over 3,000 confirmed tsunamis were deadly, and the 2004 Indonesia tsunami was the deadliest, with over 227,000 casualties.

The Soviet Union’s surprising first atomic test ended the US nuclear monopoly

In 1949, the USSR successfully tested its first atomic bomb—ending the US monopoly on nuclear weapons and sparking an arms race that would define the Cold War.

The Tsar Bomba was the most powerful nuclear weapon ever tested

In 1961, the Soviet Union detonated AN602—known as the Tsar Bomba—the largest nuclear explosion in history. Newly released Russian footage starkly illustrates the unmatched destructive power of this nuclear weapon.

The US Pacific strategy sought control of key islands to close in on Japan

The US adopted a two-pronged "island hopping" campaign across the Central and Southwest Pacific from 1943–44, deliberately targeting strategically crucial but less-defended islands. This allowed forces to bypass heavily fortified Japanese strongholds and build airfields for bombers aimed at Japan, drastically accelerating the path toward Tokyo while conserving manpower and resources.

Before World War II, the US was a Pacific power

Decades before Pearl Harbor, the US held major Pacific territories—Hawaii, the Philippines, Guam, American Samoa, and numerous island bases—giving it strategic reach across the western Pacific. This presence increasingly overlapped with Japan’s imperial ambitions in the region, contributing to rising tensions.

Meet the scientists who worked on the Manhattan Project.