The residents of Sanctuary Hills, who are also the neighbors of the Sole Survivor and their family, were sold spaces in Vault 111 by the local salesman at the time of the Great War. With nuclear strikes bound for Boston imminent, the inhabitants of the neighborhood are rushed to the vault and barely avoid annihilation by nuclear fire. They unknowingly become test subjects for the shelter's experiment on cryogenics, having all been put into stasis in the cryo-pods, under the guise of decontamination chambers.
Years later, a group of Institute operatives led by Kellogg seal the fate of the Survivor's neighbors when they sabotage the cryo-pods' life support, sparing the Sole Survivor and their family. Their spouse is murdered by the mercenary and their son Shaun is kidnapped, leaving the Sole Survivor the only living dweller inside the vault in 2287.