There was a documentary on a few days ago about WW1 female factory/munition workers. At one munition factory in the UKicon, during WW1, there was an explosion and a number of female workers were, unfortunately, killed. It was suggested on the documentary that the likely cause may have been "when the fuse was being fitted/screwed into the shell" at the factory. But I didn't think fuses were normally fitted to shells until just before they are fired or is this practice, of fitting the fuse at the last possible moment a more recent thing, perhaps WW2 onwards? Did they ever install fuses in shells at the factory?