2007 XT200 Ramp door repair

[herdbull]

So out of the blue the fiberglass panel cracked near one of the hinge mounts. This is a "new to me" camper as of last summer. Currently it is set up 3 hours away so I can't get any more pics. I'm heading back to it tomorrow but unfortunately have very sporadic and weak internet service. But I figured I'd throw it out to get the ball rolling.

Anyone ever tear into one of these ramp doors? Not sure of the construction and what I'm dealing with here. Nothing feels soft or rotten but is there even much in there to rot? The only reason I ask is because I see the little bead of caulking along the bottom of the door between the aluminum and fiberglass panel has rotten off and water could get in there.

I'm fairly handy and have no problem opening this up to repair/replace as I think this would be a very costly repair at a repair shop. With a little luck it's just the panel that cracked. But then again, why? I also did notice that a few of the hinge bolts that go through to the inside flanged nut type fasteners were a bit loose. Hopefully someone here has tore into one of these before and could offer up some insight as to what to expect.

EDIT: I did throw some duct tape over the cracked area before I left just to keep any precip from getting in.

[APD]

That's one of the hinges with the spring assist anchored around it. Probably under more tension than the outside hinges. If the bolts were loose I'd hazard a guess the inside has got soft over time, the bolts loosened and allowed the hinge (under pressure from the spring) to twist causing the crack. I don't own a hauler but my guess is there is/was wood in there.