> One hundred pounds of gunpowder had detonated from inside its storage space above the writing room.
As a non-nautical fellow, I have to ask: why did a cruise ship have a hundred pounds of gunpowder stored?
At least some of it was probably for the Lyle Gun (https://en.wikipedia.org/wiki/Lyle_gun) which was used to send a line (rope) from one ship to another to transfer people or cargo.