After driving through a puddle car with stay running

My friend drove his soon to be my car through a foot puddle it almost shut off but revved through it we stopped and parked about two hundred feet later. Went inside came out car barely started went about a mile and shut off. I took off the distributor and rotor let them dry a couple days later tried to start it rotor will not move, looked down the spark plug hole and the cam shaft is spinning. So how do I tell if it is the distributor shaft or the timing belt? And if it is not either one what else could it be? Why would a puddle cause the belt or shaft to break? What is the cheapest way to fix my new boat (car)?