It doesn't take much to form a sinkhole, especially in places where the ground has a rich deposit of karst. While California hardly has any karst deposits, stories like the Simi Valley sinkhole prove that anything's possible. When it comes to water damaged homes, it's not enough for Northridge water damage repair companies to dry the furniture and tear down the rotting drywall. The source of the leak must be spotted and patched up before it seeps into the ground and creates more destruction. That's why plumbers must be called in first to seek out the culprit before calling in the restoration services. Efficient water damage restoration companies can also work directly with their clients' insurance providers and bill these providers directly.