Aug. 3 (UPI) — Groups around the world will gather this week to commemorate the Aug. 6th bombing of Hiroshima, a nuclear attack that killed 200,000 Japanese people 80 years ago.

Events, prayer gatherings and services memorializing the bombings of Hiroshima and, three days later, Nagasaki, range from an event at a small library in Kansas and a gathering at a church in Spokane, Wash. to a series of reflection ceremonies in the Northeast and a ceremony in a park in a North Carolina park.

Japan exited World War II within days of the Hiroshima bombing, an event that changed the rules of war and elicited shock and disbelief on the global stage. The Hiroshima bombing marked the first occasion that a nuclear weapon had been used on a large scale, and raised questions about human rights and what constituted fair rules of engagement.

The bombongs of Hiroshima and Nagasaki started a nuclear arms race that accelerated over the decades and remains a constant today.

Recent data from the Pew Research Center shows a third of Americans feel that dropping atomic bombs on Hiroshima and Nagasaki was justified while nearly the same number said it was not. Another third said they are unsure if the drastic measures were warranted.

Many of the deaths were instantaneous. Other people died years later as a result of exposure to nuclear radiation, researchers have said.