In order to repopulate the American continent in the wake of a nuclear war, Vault 0 was designed as a super-Vault to preserve the greatest minds of the time and their genetic potential. Once triggered, the Calculator would oversee the recolonization and education of Neo-Americans in a new world. However, budget cuts instituted by the Department of Defense, embezzlement of already allocated funds and poor choice of brains for the Calculator's neural network resulted in what can be best described as a catastrophic failure. The brains lost control over the Calculator, inadvertently leading to the beginning of a genocide of the human population of the wasteland at the hands of the soulless machine. While the cryonic pods at Vault 0 malfunctioned, causing the geniuses to suffer irreversible, severe brain damage. Geniuses became broken toddlers, cared for by the automaton.
↑Fallout Tactics chapter cutscenes: "With your initiation now over the Brotherhood now reveals to you their highest objective. Fragments of data left over from before the Great War show that the ancients spent many years constructing Vaults to house the survivors. Recently acquired data, however, points to the creation of an enormous super-vault. This nucleus of the vault network was built to protect the greatest minds of the time and would be the spearhead of post-war civilization. If the Brotherhood could find this vault and activate its systems, they would have access to technology resources previously undreamed of, as well as access to the ancients themselves. But the journey to the calculated location of Vault 0 would be perilous. A large army and a vast area of operations would be required for a mission of this magnitude."
↑Fallout Tactics chapter cutscenes: "In the paranoid times leading up to the war, new Vaults were being constructed every day. The ancient's temples of war known as NORAD became the home for Vault 0, a storage place for the cryogenically frozen geniuses of the time. The Calculator was built to be a mixture of machine and man, a gestalt of mechanical switches and human brains linked through a cybernetic interface. Supposedly representing the ideal society, these brains were to govern the higher functions of the Calculator, powering its neural network. The Calculator was designed to oversee the repopulation of the continent in the event of a war and educate the new humanity in the ways of the old world, but first it was to sterilize the land, making a fresh start for the soon to be emerging citizens of Neo-America."