If you were unlucky (or lucky?) enough to die at Alcatraz, this is where you would have ended up; the end of an old re-purposed tunnel. No refrigeration here, but apparently it stayed nice and cool, or at least cool enough to keep the rot away until the boat arrived to take your body to the mainland.
I think what’s remarkable about Alcatraz is just how juxtaposed everything is. Right outside this room are beautiful gardens that as I understand it are essentially as they were when the prison was still in operation.