The apparent terrorist attacks on the World Trade Center will be the most costly man-made catastrophe in U.S. history, according to the Insurance Information Institute.

Insured losses are likely to be in the billions of dollars, says the III, although it cautions that it will be some time before an accurate assessment of the total impact can be made. The 1993 World Trade Center bombing caused US$510 million in insured losses. The 1995 Oklahoma City bombing resulted in insured losses of US$125 million. The Los Angeles riots of 1992 resulted in insured losses of US$775 million, previously the most costly insured man-made disaster until today.

Any determination of insured losses will have to take into account the destruction of the World Trade Center towers; business and personal property of tenants and their employees; workers compensation for injured workers; claims for lost business income; and the cost of establishing alternative, temporary operations at off-site locations.

The U.S. government is self-insured, so physical loss to government buildings is not a commercial insurance issue. Insured commercial businesses within the Pentagon, for example, could incur insured losses.

The Insurance Information Institute is located in the vicinity of the World Trade Center and operations could be affected as this tragedy unfolds.