I actually thought along the lines of some posters who conjectured about improperly conducted welding operations. I'm glad I was wrong, and that they caught a firebug.
I checked out Manchester Union Leader today and the tale is something else. Sorry no link. Sparky can send the link if you want to read some wild stuff.
It is the comments section that gets wild, one poster says the fire bugs girlfriend may be a Latino Prostitute that works undercover for the Government. His idea is the government pays hookers to date shipyard workers and Military men to pump them for information and report back if they have LOOSE LIPS.
This poster was VERY instant that this goes on all the time. Sub Contracting hookers to become girlfriends and report on what their boyfriend is doing, drinking too much, gambling, talking about Classified stuff.
Far as Sub Contractors doing any kind of check on their hired or temp workers, other then a Piss test, a #SS card and birth certificate that has to be filed, the Temp workers Agency is responsible for doing any back ground check. The Sub Contractor can in no way do all this themselves as some Temp workers leave after a few days.
The small Contractors have perhaps 6-7 full time employees [ I was one ] the rest of the workers are unknown to the Contractor. All jobs go by bidding so the Contractor has no idea how many workers they will need for a job until they win the bid. ---All kinds of hankie pankie going on there.
Some ships are cautious with Contractors working on their ships, the ships with Marines aboard were a pain in the ass. Got to PEE, need an escort to the head. 20 feet in the air whistles are blown and everyone has to freeze as these kids came through on a training exercise. Some how we had to hang on to a ladder or pipe and hold out our badge from the Contractor. The Marines had weapons but unloaded I would guess but still very unnerving to see a Marine just out of teens with a weapon checking you out.
Some how the Ship Yards function as they have for thousands of years, Ships and Boats are built and repaired, some of the workers all ways have been Lunatics, Drunk or on Drugs, not to mention Crew Members that can go daft.