Wondering if this is a broken lease?

This morning I recieved a courtesy call from the electric company informing me that on 2/15/06 they had shut off the electric because of non-payment of electric bill to my rental house. Over the weekend the temperature got down below zero. I have tenants that were renting the house and were supposed to be providing heat. I could not locate the renters so I went to the rental and the pipes were frozen and it looked like the tenants had abandended the property because there was no furniture and keys were on the counter. I had the electric turned back on and tonight the water started flowing and I did not see any pipe breakage. I have a year lease with 8 months remaining. The rent is paid up until March 1 but I am wondering if I should try to mitigate my damages by re-renting the house because they have broken the lease? I have left messages and am waiting on a reply from them but I am wondering how long I should wait and what actions I need to take? Thanks for any comments anyone will furnish.
Sincerely

No need to wait – they’re gone. Get it rented as soon as possible.

I agree. Doesn’t look like they are coming back.