What is the insurance company responsible for?

It depends on your policy.  There are several types of homeowner's insurance policies.  The most common policy is a HO-3 policy. HO-3 policies often provide insurance coverage in the event of an unforeseen circumstance, including damage from fire, lightning, wind, theft, or certain events causing water damage.  However, every policy is different and each claim needs to be reviewed by a trained eye before making a determination on whether your claim will be covered or not.