The facility was located way out in the sticks in a southeastern state on about 50,000 acres of government land, heavily wooded. I think I heard banjos playing in the background.
The manufacturing building was long and narrow. The interior was a corridor running the length of the building along the exterior wall. Running along the corridor most of its length were the manufacturing cubicles back to back. Each cubicle was heavily built for explosion containment. Automated equipment inside would perform one step of the assembly than pass the munition through a trap door down the line to the next room.
The door to each cubicle was steel about 6in thick, locked from the outside and had a small 6in thick glass viewing port. In case of fire, a deluge water system would flood any or all 12ft x 12ft cubicles floor to ceiling in less than 15 seconds. The manufacturing is all automated now. In WW2, there were 2 or 3 people in each room. No escape, like I said, the doors locked from the outside.
The fire fighting system I designed for the outside equipment and adjacent tanker truck loading dock would bury everything under a mountain of firefighting foam in about 30 seconds. An additional water tower was installed so this was not in short supply.
Why bury everything under a mountain of foam? Sometimes you need to design something to an extreme level of KISS (keep it simple stupid). For redundancy though, I equipped 2 fire monitors in the area with quick connects for the foam chemical and built a small garage building to house a tanker trailer that fire fighters could rapidly hook up to a pickup truck. This portable foam chemical tank could also hook to the primary equipment's foam deluge system as a redundant supply.
Crane?