Vault 144

Vault 144 is a mentioned only Vault in Fallout Shelter

It is mentioned in the quest "Give me Liberty and/or Death" in the quest line "Horsemen of the post-Apocalypse part 2" in Fallout shelter.

Background
The Vault is obsessed with Death after either a misspelling, but more likely intentionally by Vault-tec where every spelling in the vault manual of Death is spelled with a Capital D.

They are portrayed in the Game as waiting for death, and about quotas of Death, to advance the arrival of Death