There's something I either can't tell from the picture or can't figure out. There is NO rust on the now exposed edges of metal. The galvanizing is only a coating so the break isn't galvanized. You obviously had an all at once, catastrophic failure on your way home. Did you hit something or drop a tire off the asphalt in a curve? It's hard to break 2x4 tubing, even 14 gauge like that appears to be. He's going to have to scab the metal from the inside of the tubing or your spring hangar bolt will no longer fit. Plug weld, plug weld, plug weld.
The guy that fixes it may think to do so, but in case he doesn't, unhook your wiring from your brake lights. Tie a piece of welding wire to it and pull it back up towards the tongue. Welding and plating over that crack will melt your light wires.