If it's any consolation, Hanover isn't the only company that may need to drastically lower its full-year earnings forecast because of Sandy. Chubb ( NYS: CB ), Travelers ( NYS: TRV ), and Allstate ( NYS: ALL ) all stand to face rough waters in the coming quarter or two as they assess the true financial impact of the storm. Even reinsurers like Berkshire Hathaway ( NYS: BRK.B ) are poised to take a big hit from Hurricane Sandy -- Berkshire reports in a few months. What's worth remembering here, though, is that these insurers handle one-time catastrophe losses for a living. Although the forecast for these companies may appear bleak now, catastrophes of Sandy's magnitude give insurers valid reasons to raise premiums, which quickly help to wipe out one-time losses. It's also worth noting that flood damage isn't often covered by standard homeowners insurance, which may ultimately get many of these insurers off the hook.