The same issue (I think) can be seen in Post #1 in this thread
https://www.trailmanorowners.com/for...ad.php?t=17530 and its picture. Once you get it upright, the pic shows a bracket at the end of a torsion bar. The bracket was supported by 4 lag bolts that went upward into the edge of the wall, and into the wooden 2x4 floor frame. The pic suggests tht the lag bolts pulled out, the bracket and the torsion bar fell, and the wall of the shell dropped with it.
. I believe that at some point well after the post was made, TM stopped using lag bolts into wood, and started using large machine-screws (hex bolts) into nuts located on the top of the 2x4 floor frame. Probably T-nuts. The same thing happened to me - the bolts simply backed out of the nuts, and the bracket fell. Much to my surprise, I was able to stuff the hex bolts back into the holes, give them a couple turns by hand until the threads caught, and then torque them back up into place.
. I don't know when that change happened, but certainly within the past few years. If your TM has lag bolts in this location, the fix may be to upgrade to the new approach. Cut a short, wide window in the back wall of a kitchen cabinet at floor level, to gain access to the inside of the wall at floor level. Bore out the holes that were used for the lag screws, install some T-nuts on top of the 2x4, get some matching hex bolts, and screw the bracket back up into place.
Another possibility is that a lift arm has slipped down, though this is not common unless someone has tried to adjust it. Go to this thread
https://www.trailmanorowners.com/for...ad.php?t=18230
and look at the picture in post #5. It shows two of the lift arms, one for the front shell and one for the back shell. If the four bolts in one of them come even slightly loose, the lift arm can slide down on the vertical (in the picture) end of the torsion bar. The bolts must be very tight.
If any of this gives you some clues, come back to us and we'll try to follow up. By the way, "2028" is not a valid model name. Maybe a 2720? For the record of a donation, an accurate model number may matter.
Bill