Span across with angle iron on the bottom and a strip of 1/4" thick metal strap on the top. Drill bolt holes every six inches or so and use round head machine bolts fed from the top. Visualize it as sandwiching the end of the loft between two very strong and stiff pieces of metal. Grind away any excess bolt on the bottom and then fabricate a padded fabric cover. Even better would be if you could find a machine shop and have the angle iron holes tapped for the bolt thread. Then you could grind the excess bolts flush. Much more work than some other options, but it would be the strongest repair.