Rural Germany 4 AM on a Sunday in late June 2019; a loud explosion tore up a cornfield leaving a large crater. Police went in to look at the ten meter (34 foot) wide crater and found it to be at over three meters (10 feet) deep. Police called in bomb disposal experts, who still get a lot of work in Germany. The site of the cornfield explosion was between Cologne and Frankfurt, an area that was heavily bombed by British and American bombers during World War II. The cornfield apparently had at least one 500 pound (228 kg) bomb that did not explode. During World War II a lot of these were dropped and over five percent of these bombs did not explode. Many of those landed, were covered by debris from other bombs, and only discovered later when construction crews dug up an area to build something. Not much of that construction activity occurred in rural Ahlbach, which never had the railroad facility rebuilt after the war and became just another rural farming community.
It was unusual for the fuze of such an old bomb to suddenly go off after being in the ground 75 years but it does occasionally happen. Back in 2010, 800 meters off the coast of the Pacific Island of Okinawa, a phosphorus bomb dropped 65 years earlier finally went off without any human intervention. That bomb had been dropped into shallow coastal waters in 1945 when U.S. troops invaded the Japanese island. Decades of tidal action and storms moved the bomb to shallower waters, until, exposed to the air, the phosphorous ignited. This is what phosphorous does when exposed to the air. That created a column of white smoke that surprised people on the nearby beach. Japanese bomb disposal teams showed up to deal with it and found another unexploded bomb nearby, as well as a 105mm artillery shell. This was not the first time such a delayed bomb went off in the area. The last occurrence was in the 1970s and there has not been another, yet. There will be unexploded bombs, shells and grenades found on Okinawa for a long time and the local bomb disposal teams expect to be busy for decades to come.
Back in Germany, about a hundred unexploded bombs and shells are found each year, mainly by construction crews in urban areas. Some are larger (four to twelve times heavier than the cornfield bomb) and nearly all are safely disarmed by the bomb disposal terms, who then carefully remove the bomb for disposal (explosives removed and neutralized while the casing becomes metal scrap). Sometimes the bomb disposal team determines that the fuze is too unstable to be safely disarmed and the area is evacuated and the bomb destroyed by detonating it. That is rare but there are times when there is no other choice but to evacuate a wide area and then repair lots of blown-out windows and other damage.
A few former combat zones contain so many unexploded bombs and shells in a small area that a “Red Zone” is created. These are mostly along the World War I era Western front where over a hundred million unexploded shells, bombs and grenades were left behind after four years (1914 to 1918) of fighting. In France, where most of these shells landed, several hundred tons of unexploded World War I shells are still found each year. While 630 Frenchmen have died since 1945 dealing with the unexploded shells as time goes by the remaining stuff becomes less lethal. The last death in France from World War I era dud munition was in 1998. Yet there are still lots of these duds in the ground and it is known where areas are the most “contaminated.”
Because of very heavy concentrations of duds, there are still parts of the Western Front that remain off-limits to civilians. France did a survey of the Western Front right after World War I and drew up a map showing the areas where the danger was greatest from unexploded munitions. The most dangerous areas, designated “Red Zones”, covered 1,200 square kilometers in 1919. That has shrunk over the years to their present size of 168 square kilometers, most of it around Verdun. These century-old explosives, many of them chemical weapons shells, are too unstable to go looking for. Every year some work their way to the surface. If these areas were not fenced in after the First World War, many more farmers or hikers would encounter and often die, from these old shells and bombs that had reached the surface. Between the World Wars (1919-1939) there were many such casualties in the “Yellow Zones” where people were allowed but warned to be careful.
Despite the huge quantities of shells fired on the Russian Front in both World Wars, you hear little about unexploded munitions because the Russian Front battles were fought over a much larger area and the communist era command economy meant little new construction. With all the post-Cold War construction now going on in Russia a lot more of these old munitions are being found, but most of them from World War II. For example, in 2013 two men died when a World War II era artillery shell went off as they examined it in a forest outside Kaliningrad, which was the German city of Konigsberg until it changed ownership at the end of World War II. Earlier in 2013 two railroad workers were injured when they triggered a World War II era landmine outside St Petersburg (formerly Leningrad). In Western Russia, police arrested a man in 2013 who was trying to sell five 81mm mortar shells he had found. He found six but tested one by tossing it in a fire, taking cover and then noting that the 65 year old shell exploded. These shells weigh 4-5 kg (8.8-11 pounds) and about twenty percent of that is explosives (most of it high explosives, the rest propellant). In most parts of Russia, the local governments offer a reward for people who turn in ancient munitions, or better yet, don’t try and move the stuff and just report the location. But this guy either didn’t know about the rewards or figured he could make more by selling the five shells. Most people had better sense than to buy elderly munitions and word of the sales activity eventually got to the police. These rewards are not the only continuing cost of World War II. There are also heavy expenses for special teams of technicians who can safely remove these ancient but still deadly munitions.
Some of the worst problems take place on Pacific islands that were fought over during World War II. For example, the U.S. has spent over $50 million to remove World War II era bombs and shells on Guam, as new bases for troops are constructed since the 1990s. Over the last few years, the bomb disposal teams on Guam were called out 4-5 times a week, 70 years after World War II ended. These small islands had far more bombs and shells used on them that the comparatively vast areas of Europe.
It’s not just aircraft bombs. Most of the explosives unearthed are smaller items like grenades, mortar shells, rockets and mines. Many bombs, artillery and mortar shells (over ten percent, for some manufacturers) did not explode when they were 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 got buried and lost. Most of these lost munitions eventually get found by farmers, or anyone digging up the ground for construction. Most large cities, Europe and the Pacific, that were heavily bombed cities during World War II, still suffer from construction crews unearthing unexploded bombs. In Russian cities, you tend to find lots of artillery shells that were fired by both Russian and German troops.
The problem goes back farther than World War II. Unexploded munitions from 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.