Repairing a small crack in the roof of my camper trailer

Looks to me that there's more going on than simply a crack appearing. Looks like there's a large and a small crack. Looks like something structural is coming apart and maybe something was never fastened with a screw or bolt. Maybe there was a small crack that occurred awhile back and after a while of exposure to the elements, there might be some structural failure. I think I would check first before trying to seal it up.