On the Japanese island of Okinawa, the operator of a excavating machine was injured when a World War II bomb or shell was struck by the powered shovel on the machine. The explosion left a crater five meters wide and nearly two meters deep. The machine operator was thrown from his seat, and suffered cuts to his face and chest. The excavator was digging a trench for a new water pipe, and the bomb went off less than ten meters from a retirement home. Windows were shattered and debris was thrown up to a hundred meters away. Fortunately, the 160 residents of the retirement home were in the cafeteria having breakfast, in a part of the building not facing the explosion. Many would have been injured by flying glass, had the explosion occurred at another time, as over a hundred windows of residents rooms, were blown in. In the last 35 years, 54 Okinawans have been killed or injured in similar incidents. Just last Fall, another unexploded World War II warhead was found inside the U.S. Kadena air base on Okinawa. Bomb disposal experts removed the five inch (127mm) aircraft rocket to where it could be destroyed. Bomb disposal experts estimate that 2,500 tons of munitions still lie buried all over the island, and that these weapons will remain a danger for another century.
Okinawa was the scene of a major battle during World War II, where millions of shells, rockets and bombs were used as invading Americans fought Japanese defenders. Most of the of the buildings on the island were destroyed by these explosive devices. But many of those explosives did not go off, and were buried in the rubble and earth. Since then, every few years, more are uncovered. The rocket found last Fall was near one of the base entry gates, a hundred meters from a residential neighborhood. Everything in the area was shut down for half a day, as bomb disposal teams came in to disarm the weapon and haul it away.
World War II era munitions continue to show up throughout Europe and Asia. Although most of the millions of land mines were removed from combat zones within a few years of the war ending in 1945, there are still a huge number of unexploded of grenades, shells and bombs buried all over the place. At least the mine fields were easy to find, although dangerous to clear. But the remaining munitions were left behind, in unrecorded locations, for some pretty simple reasons. First of all, many (over ten percent, for some manufacturers) bombs, artillery and mortar shells do not explode when they are supposed to, but just buried themselves into the ground. These shells are still full of explosives, and often have a fuze that, while defective, is often still capable of going off if disturbed. Other munitions were left in bunkers, or elsewhere on the battlefield, and get buried and lost. During the World War II battle for Okinawa, the Japanese troops used hundreds of caves, and many may never be found. Many other lost munitions eventually get found by farmers, or anyone digging up the ground for construction. London, Tokyo and Berlin, three of the most heavily bombed cities during World War II, still suffer from construction crews unearthing unexploded bombs.
The problem goes back farther than World War II. Unexploded munitions from the World War I (which ended in 1918), and the American Civil War, which ended in 1865, are still showing up, and some of them are still deadly. Currently, over a thousand World War II munitions are discovered each year in Europe.