I should also add that yes we were running these exhaust fans regularly after showering so I am hoping these ducts recently became disconnected but I am guessing this likely happened in the summer when we had about a week of 95+ degree weather and that's probably what dried up the adhesive on the already lousy duct connections.

What you need is to find out if water is coming in or were the vents really the whole problem. As far as the mold itself goes, a bleach solution should take care of it, but if the source problem is not dealt with, it will return of course.

As far as the mold itself goes, a bleach solution should take care of it,

Bleach is ineffective in cleaning mold. It is now recommended to use Borates since it has been shown effective in also killing the mold spores which can penetrate the wood since it is porous. Mold isnt something you want to be messing around with. I would recommend calling a few mold mitigation companies to get some estimates and see what you're really dealing with.

The first step is to identify the type of mold. Not all molds need to be professionally removed. Once that is determined, then find out the best remedy for the type.

I have found a potential solution....Concrobrium Mold Control. Everyone swears by it and it's used by remediation companies.

How is the attic constructed? Is the insulation under the roof or under the attic floor? Are there vents along the soffit (down by the gutters) and on the roof peak? Are there vents at the gable ends (triangular wall sections at the ends of the house)?

What I'm getting at is, will the extra moisture be vented out or has it all been trapped in the attic for a year. If the attic is well ventilated, maybe cleaning surfaces and reconnecting the vents is all you need to do. If it's basically sealed up, you might need to dehumidify it.

You mention "black mold" in Los Angeles area & they rip your house apart. I saw the mess they made of Erin Brockenvitch(or whatever her name was(Julia Roberts played her in movie about different problem) anyway several houses in area of her house got tore to shreds. Well, they were fairly close to ocean so you naturally get lot more mold growing. Most houses have some mold, just take a Qtip & put it in your sink drain in bathroom, run it around & in most cases it will be black!! I have allergies so I have narrow brush that is on end of 6 ft cable so I can scrub it out, I use Comet & rinse well & then hydrogen peroxide& forget about it until next time I clean it. A lot of times the "black" or dark spots in attic is from moisture getting in before the new roof was put on(reason they put new roof on!

If you still have the issue a lot of pest control companies do mold removal and treatment.

Before you are swayed by a mold remediation company, read and understand this:

http://www.forensic-applications.com/moulds/sok.html

Most of the people who do mold remediation are not scientists and they have no specific training to even know what they are dealing with. They only rely on the power of fear and how strongly fear affects persuasion.