I am still baffled that back then people could not build mechanisms to set a bomb off reliably, yet could build bombs that remained deadly while lying in the ground for what now amounts to a decent human lifetime. And I am deliberately ignoring the legacy of World War I here, which according to the latest forecasts will still take centuries to clean up.
The difficult bit is making a bomb that goes off reliably but not before. Explosive stabilisation is the innovation that made the Nobel fortune, remember.
Then be really worried, the amount of munitions dumped at sea is staggering[1]. A US bomb was found around Fukushima near a car park [2]. People tend to ignore the amount of munitions and equipment scattered all over the Pacific and adjacent nations from Japan's attempt to conquer the area during WW2. Their build up while not as impressive as some of the German construction was just as destructive
