Fallout 4: All 5 Vault Locations & Their Creepy Backstories

4. Vault 75

With its positioning under Malden Middle School (in the north-eastern part of the Wasteland), Vault 75 was built with the purported purpose of saving schoolchildren - along with their families and teachers - when the bombs fell. But when the kids were taken down into the vaults, all their accompanying adults were taken to another room and killed by the Vault security personnel. The children, meanwhile, were vigorously tested for their physical and intellectual abilities until the age of 18, as a means of picking out those with the best genes. At the age of 18, the physically-gifted children were harvested for their genes, the brainy ones went on to 'graduate' and become members of the Vault's science team, while the rest were deemed unworthy of remaining in the Vault's gene pool and subsequently disposed of. It's quite possible that Vault-Tec's plan was to build a private army to help them become a serious power in the post-apocalyptic world. Eventually, with the help of one of the former test subjects who graduated to work on the research team, the kids rebelled and managed to escape the vault. When you visit the vault, you'll see signs of a violent struggle, though notably the only casualties appear to be adults. While it's not clear when exactly the rebellion happened, there's a good chance that some test subjects, or their descendants, are out there in the wasteland.