This can be a business. All through out the south or anywhere really, except Cali and other earthquake prone states.
Seems like a great cheap idea to do it yourself. Digging the hole would be difficult but not impossible. Then you could just drive the bus into the hole. Leak proofing shouldnt be too tough. Soon as it becomes a business they will find some way to make it super expensive. Or find a way to say its against building code to bury a school bus.