Honda 1996 HX won't start because of air bag sensor?

My son has a 1996 Honda HX that already had the air bags deployed prior to him purchasing the vehicle. The vehicle ran fine until... Just last week he ran into the ditch during a snowstorm and it must have set off the air bag sensor circuit from the impact. Now everytime we replace the system fuse it blows when the key is turned on. How can I bypass, fool or disable the air bag circuit so the car will start?

Also, if anyone has found a cheap 5 wire oxygen sensor replacement for this vehicle it would make a great Christmas present for me to give him.

Thanks so much. He has no money to take it to a dealer for repair.