| ||For other characters named Daniel, see Daniel.|
Daniel Koster was an engineer living in Vault 87.
Koster was stationed in a small engineering room off the atrium's upper level. As time went by, he grew more and more suspicious of the secret experiments conducted in the vault, eventually choosing to confront the people he considered responsible after the mysterious death of his wife.
His safe is unlocked by accessing the last entry of his terminal.
Interestingly enough, his wife, Mercia Koster, was not the subject of any experiments with F.E.V.. A medical research terminal lists her as dead with code "N009", alleging that she had a form of type I cancer.
Daniel Koster is mentioned only in Fallout 3.