broken pipe - who is responsible

[Donna Salmiery]

I closed on a townhouse on 3/18. I had a home inspection done on 2/11 and there were some issues that were fixed, but the report mentioned no issues with pipe that goes to the outside faucet. The tenant moved in 4/1 and when he turned the main water valve on (there are 2 valves), he could hear water "gushing in the walls" He turned that valve off and still had water by the other valve (sorry for my complete lack of knowledge on this). I called a plumber 4/4 and he went right out and there was a broken pipe leading to the outside faucet which he said it appeared had froze and broke. I called the water company today (4/14) to make sure the tenant had switched the water to his name, and they told me my final bill for the time period since 3/18 (not sure the exact date tenant switched over), but it is less than one month is $1175!! I asked the plumber if there was any way to tell how long it had been broken, ie. corrosion, and he said no. He said it would be something the home inspector definitely should have caught. So it may have happened AFTER my inspection. But here is the thing: I had gotten a bill for 3/18-3/21 and it was for $134 (water and sewer), so that tells me that the leak was already there 3/18, right? I didn't ask the seller what the usual water bill was (mistake). So do I have any recourse anywhere? If there was a problem and the seller knew, do they have to disclose? How could I know if it was there and the inspector may have missed it? Would my owner's insurance cover? The plumber bill was only $100. Thanks for any advice for this newbie landlord!