The Manhattan Project National Historical Park will ring the International Friendship Bell 76 times on Friday morning, August 6, to commemorate the effects of the atomic bombing of Hiroshima 76 years ago.

The bomb was dropped on Hiroshima, Japan, at 8:15 a.m. on August 6, 1945. It was the first atomic bomb used in war and the first of two dropped on Japan near the end of World War II. Uranium for the first bomb, which was code-named “Little Boy,” was enriched in Oak Ridge. The bomb had about 140 pounds of uranium fuel and had an explosive force equivalent to 15,000 tons of TNT, according to Atomic Heritage. Between 90,000 and 166,000 people are believed to have died from the 10-foot, 9,700-pound bomb in the four-month period following the explosion, Atomic Heritage said.

The National Park Service is calling the August 6 ceremony “Days of Peace and Remembrance.”

“During this silent event, we will be requesting visitors to come up and ring the bell,” a press release said. “Visitors will be able to write down their own hopes and messages of peace.”

The United States dropped a second atomic bomb, a plutonium-fueled weapon, on Nagasaki, Japan, on August 9, 1945, three days after the Hiroshima bombing. It had about 13.6 pounds of plutonium fuel and an explosive force equivalent to 21,000 tons of TNT. About 80,000 Japanese died by the end of 1945 because of that bomb, which was called “Fat Man,” Atomic Heritage said.