During World War II, much of Kolonia was destroyed as some 118 tons of American bombs, 600 incendiaries and naval artillery targeted the town and island installations. Pohnpei was bypassed during the amphibious island hopping campaigns, but rusting wrecks of Japanese military equipment, downed airplanes and bunkers are still visible throughout the island.
Kolonia's destruction during World War II is attributed to heavy bombing by American forces, including bombs, incendiaries, and naval artillery. The island's installations were also targeted.