If it's directly above the wheel well and it ripped through luan. It most likely looked like part of that lovely sandwich they used as the flooring. I know on my now sold Bullet that's what they used. That styrofoam was 1.5" deep and then a 1/4" piece of luan then the darco. I could not readily find 1.5" styro so I used 2 layers of 3/4" and used Gorilla spray adhesive with each layer, tip- use the spray adhesive to put the darco on as well. Better to overlap if possible and trim with scissors.
I didn't take pictures of the next steps, too much on my mind other than the trailer. I cuss too much for youtube

First picture is while trimming the wound. The second picture is the second piece of styro. After that layer I caulked the minor gaps with PL premium polyurethane adhesive, let it cure, then sprayed adhesive for 1/4" plywood.