When the news leaked about the Vault Tec program it cause a great deal of outrage in Detroit. News broke that Vault Tec had received kickbacks from the governments of several counties and cities in order to secure Vaults in those locations, with the stipulation of reserved seats for certain figures and their families. This, combined with information about the cost of the Vault tickets, made it seem like a frivolity reserved for the wealthy. For most of the working class population these Vaults would be out of reach. They felt abandoned and this further increased the already brewing discontent among the citizens. Vault Tec tried to assure the public by reserving some seats to be randomly selected. This gave Harold Anglin, a Detroit businessman, an idea. He had made a fortune on a patent and announced he would build a vault that was truly "for the people". To this end he ordered the construction of a supposedly massive shelter, with a capacity for 25,000 people (50,000 with double bunking). In order to make the Vault affordable, 10 tickets would be sold for each spot, with a random chance of selection upon an incident. Tickets were sold at a fraction of a cost of a Vault Tec seat and financing was offered to low income families.
Anglin was instantly the most popular and celebrated man in the city. He made appearances at sporting events and was even given a medal for his contributions to the safekeeping of Detroit. Unbeknownst to most, he had already sold off most of the spots in the vault to the wealthy who hadn't been able to get into Vault tec because of the demand. He had also sold to the poor more than 100 tickets for each slot, and promptly shredded the ticket and customer information upon receipt of payment. Anglin once privately remarked "what sort of idiot could possibly believe we would hold a raffle in the middle of a nuclear war and call the winners to give them a spot in our fallout shelter?" And unbeknownst to even his private confidantes who bad bought their spots, the shelter was never even close to being completed. Only the first floor had been finished by the time of the war with excavations made for the second and third. Various construction crews had been filtered in and out over the years doing work, which made it difficult for anyone to keep track of the progress. Anglin claimed it was operational but that it was being constantly improved and expanded to allow for more slots.
When the bombs fell thousands of people rushed to get inside, uncaring if they had won or lost the raffle. They arrived to find a shelter less than a quarter finished, with a door that wouldn't properly seal and no supplies stockpiled. The only thing that worked was the water, which had been connected to a city water supply as part of a deal with a local councilman to get him and his wife a slot (they were incinerated in traffic by a Chinese bomber anyhow). This supposed act of charity would be a blessing and a curse. The water was heavily irradiated and only made things worse, prolonging the suffering of the inhabitants if anything. When the dust had settled outside the vault, thousands of people were crammed into a space that couldn't fit a tenth. The weak were pushed into the unfinished sectors. Anyone with a gun was assigned to holding the door as desperate survivors from outside tried to force their way into the shelter. When the black rain fell that was no longer a problem. The only remaining issue was a lack of food and constant irradiation. The first to die were almost immediately eaten. When there were no more corpses but still hungry bellies it only took marginally longer for someone to decide to eat a living person. Those with guns hunted those without. An orgy of violence, cannibalism and murder followed. Sustained off the flesh of their fellows and irradiated water, a significant portion of those inside the Mercy Vault would become ghouls. They eventually abandoned the vault when they realized radiation no longer effected them... but those who survived would be marked by their actions. They would become the nexus of the organization known as "The Forsaken" which rose to prominent a century and a half after the war ended.
The ghouls would return to the Mercy Vault in the 2260s, following the outbreak of open hostilities with the Red Star Army. They would utilize it as a refuge and later a military base, being nearly impervious to conventional attack.