Reflection & Remembrance

Two people in front of luminarias lining a path look at a river in twilight,
Luminarias line a path along a river during one of several "Days of Peace and Remembrance" events.


An image of Japan with two black dots to denote the cities of Hiroshima and Nagasaki.


On August 6, 1945, a B-29 Superfortress, the Enola Gay, part of the 509th Combat Group of the United States Army Air Forces, dropped "Little Boy", the world’s first atomic bomb on the city of Hiroshima, Japan. This enriched uranium device was the most powerful weapon ever used at the time and killed between 70,000-140,000 people, many of them instantly.

Three days later on August 9 at 11:02 am local time in Japan, a bright flash of light, far brighter than the sun, illuminated the city of Nagasaki through a cloud-covered sky. Soon, a sharp boom rang out. The United States dropped the plutonium-fueled atomic bomb "Fat Man" on the city. Shockwaves destroyed the immediate surroundings of the blast’s center. Within 3,000 feet (900 meters) of the bomb's hypocenter, schools, hospitals, places of worship, and other institutions felt the impacts of the bomb. The blast instantly incinerated everything nearby: people, trees, homes, cars, and buildings.

By the end of 1945, more than 200,000 people died as a direct result of these two bombings. In addition to the immediate deaths, tens of thousands more people suffered physical and emotional traumas that have not yet healed.

Many complex decisions during World War II led to the Manhattan Project and to the development of the world’s first atomic weapons. The dropping of the atomic bombs on Japan and the destructive power of nuclear weapons prompts us to confront the profound choices and consequences of the Manhattan Project, which many still struggle with today.

Explore "Days of Peace and Remembrance" to learn about park events that mark and recognize the historical trauma of the atomic bombings of Japan. Articles in "Seeds for Reflection" will help you on both a learning and reflective journey.

A man and two small children sit on a wall looking toward a large brass bell.
Days of Peace and Remembrance

Learn about the park's commemorative events with Days of Peace and Remembrance.

A white luminaria bag rests next to a small flowing stream.
Messages of Peace

Hanford, Los Alamos, and Oak Ridge all host events where the public can write messages of peace on luminarias.

Several colorful origami cranes, pieces of paper folded in the shape of birds.
Seeds for Reflection

Start a journey of learning and reflection with these articles and other materials.

A park ranger stands in front of a large brass bell at dawn.
Oak Ridge Bell Ringing

Oak Ridge hosts the ringing of the International Friendship Bell on Aug. 6, the anniversary of the atomic bombing of Hiroshima.

A pond in a city park with luminarias lining the perimeter.
Los Alamos Lights for Peace

Los Alamos hosts a reflection and remembrance event on Aug. 7.

Several dozen people gather in a city park at sunset.
Hanford Lights for Peace

Hanford hosts a Lights for Peace in the Tri-Cities, Washington on Aug. 9, the anniversary of the atomic bombing of Nagasaki.

Three women walking in sunlight holding several luminaria bags.
Partners in Commemoration

Our park partners with other parks and organizations to host commemoration and messages of peace events.

Several illuminated luminaria bags at dusk.
Virtual Lights for Peace

Experience a virtual "Lights for Peace."

A large brass bell surrounded by luminaria bags at dawn.
Virtual Bell Ringing

Ring the International Friendship Bell virtually beginning at 6 am EDT Aug. 6 through Aug. 12 at 9 pm PDT.


Last updated: October 10, 2023

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Contact Info

Mailing Address:

Manhattan Project National Historical Park
c/o NPS Intermountain Regional Office
P.O. Box 25287

Denver, CO 80225-0287


Hanford: 509.376.1647
Los Alamos: 505.661.6277
Oak Ridge: 865.482.1942

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