Hundreds of thousands, if not millions, of insurance claims will be filed because of Hurricane Sandy, and insurance companies will take a big hit as a result. So who will be most affected? 

Berkshire Hathaway (NYSE:BRK-B), Allstate (NYSE:ALL), and Travelers (NYSE:TRV) are the three top property and casualty underwriters in New York, so they will see a big impact. In the Northeast, we can bring AIG (NYSE:AIG) and Chubb (NYSE:CB) into the fold as top underwriters. With estimates likely to exceed $20 billion, these companies will be the big losers of Hurricane Sandy. 

The impact won't be devastating, but it will hurt the bottom line, especially if damages increase as the days go on. Insurers have had a relatively light storm season, but this single Frankenstorm could change everything, even for Berkshire Hathaway this quarter.

See more in the following video.

Fool contributor Travis Hoium owns shares of Berkshire Hathaway. The Motley Fool owns shares of AIG and Berkshire Hathaway and has options on AIG. Motley Fool newsletter services recommend American International Group and Berkshire Hathaway. Try any of our Foolish newsletter services free for 30 days. We Fools don't all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Motley Fool has a disclosure policy.