Gary Kerney is assistant vice president of Verisk's PropertyClaim Services.

Tropical Storm Isaac keeps interesting company—it's an “I”storm.

Over the past 11 years, the World Meteorological Organization(WMO) retired seven “I” names because of the insured and economiclosses those weather events caused, making this one of the mostdangerous letters in the hurricane community.

Five of the seven storms with retired “I” names together causedinsured property losses of $26 billion.

Although the impact at landfall for some of these storms waslimited, WMO retired their names because of the intensity theyreached at some point. Hurricane Igor resulted in $70 million ininsured losses on the eastern Canadian coast in 2010, according toProperty Claim Services (PCS) estimates.

Estimates are not available for Hurricane Iris, which struckCentral America. Hurricane Isabel, however, which hit theChesapeake Bay region of the United States, reached Category 5strength at one point when it was northeast of the Antilles.

Learn more about PCS catastropheestimates.>>

The following table lists the retired storms and the impact ofeach, noting PCS estimates of insured property damage.