UXO buried in the ground for 70-80 years is constantly exposed to the elements with rain water having a significant effect. This can allow chemical crystals to form within the munition which makes it unstable, to the point that the smallest movement could set it off. Experts describe this process as explosives “sweating”. Despite being very uncommon, these accidents unfortunately happen from time to time.
It is quite a common type of shell to find, especially in the north of the country. A lot of the bombs dropped between December 1944 and January 1945 never exploded because of heavy rainfall. The rain produced a lot of mud, which softened the impact of each shell and many didn’t detonate.
Luxembourg was the scene of several land battles during WWII and consequently UXO contamination is a problem. The Luxembourg’s demining service (SEDAL) performs some 250 UXO disposals per year.
Are deaths by UXO common?
A shell explosion in central Europe is not a common occurrence, with such incidents relatively infrequent across the continent. This is the result of relatively good education, lower levels of poverty, less fragile UXO types, and lower UXO concentrations.
The most heavily contaminated region in the world is Southeast Asia where UXO related deaths are frequent. The U.S. air force dropped >270 million cluster bombs during the Vietnam War and approximately 80 million failed to explode.