As a result of all the groundbreaking information occurring in the insurance industry as a result of the World Trade Center, facts are emerging and changing by the second - so unfortunately last week an incorrect version of my column was printed in error.

As such it is both an exciting and worrisome time to be starting an insurance column because in the haste of meeting deadlines sometimes the wrong information is sent and reported.

The first error in my column was the definition of Cat 48. After checking with property brokers, I was told Cat 48 meant it was the 48th catastrophe in the world but as I've often said, we must follow our instincts, and something nagged at me to research the topic a little further.

Following that nagging feeling, I contacted the Insurance Services Office (ISO) in New Jersey to find out how they came up with the term Cat 48.

Ms Marian Jones, of the international department of the Insurance Services Office provided the following explanation for what Cat 48 means and how they classify incidents as catastrophes: "For your purposes in 2001 there were 13 ISO catastrophes before September 11 - 14 with the assignment of Cat #48 for the attack on America.

The following will explain the numbering sequence. Each catastrophe is assigned a serial number, also known as a 'Cat number'. The Cat number is not a unique identifier. A number from eleven to 99 is assigned to each of the catastrophes during a calendar year.

The numbers are used consecutively, not chronologically. That is if the last catastrophe number in one year is 35 the first Cat number used the next year is 36.

As a result, the same catastrophe numbers have been used for various events, and catastrophe numbers can overlap. For example, in 1990, catastrophe number 26 caused $35 million in damage in Alabama. In 1995, catastrophe number 26 caused $225 million in damage in California. These are two totally unrelated catastrophes, but they share the same Cat number. In 2001, ISO began with the number 35 so as of September 11 there were 14 catastrophes that met the ISO catastrophe definition. Number 48 includes the NY WTC and the Pentagon in Virginia. As of today, we are on Cat number 52.

The ISO definition of catastrophe is 'an event is classified as a catastrophe when the following criteria have been satisfied:

1. The catastrophe must cause enough insured damage to fall within the dollar threshold - for 1997 to the present the amount is $25 million. 2. It must affect thousands of insureds who have incurred losses from the event. 3. The event must take place in the United States, Puerto Rico and/or the US Virgin Islands'.

I rewrote my column without the explanation for Cat 48 because I felt the above explanation was cumbersome and irrelevant to its content. However, for the record, this is the correct information. The second issue was that at the end of the day on October 26, 2001, new information about the Silverstein v. Swiss Re case emerged, suggesting that the insurance contract between Swiss Re and Silverstein properties had not been finalised at the time of the loss and as such there was more at stake than just the interpretation of the policy wording. At issue is not just the definition of an occurrence but how the policy would have responded to the loss as a result of the definition of occurrence if it had been finalised.

The Silverstein lawyers have also uncovered a 1959 rainstorm case called Arthur Johnson vs. Indemnity Insurance which arose from an insurance dispute about the definition of occurrence and a paper trail that allegedly reveals that no insurance cover had been finalised by the day of the loss. Apparently the case revolved around a rainstorm which caused separate walls of separate buildings to collapse which prompted an appeals court to rule that the catastrophe was not the rainstorm but the collapse of the walls, thereby treating the incident as separate occurrences. The Silverstein lawyers are planning to use this case as the precedent for their case of defining the World Trade Center incident as two separate occurrences. As a result of this finding, I deleted the reference to 'to the best of my knowledge, never in the history of insurance has there been a doubling of policy limits for a loss stemming from the same event'. As the original version of the column was printed that line unfortunately remained.

I further discovered an analysis completed by Peter Hirst, a partner and Charles Bending, an associate specialising in insurance and reinsurance litigation for the UK law firm Beachcroft Wansbroughs in which they debate the definition of occurrence, event and cause and their application to the US hijackings.

In the UK and other countries there have been several cases which have debated the definition of occurrence in the event of terrorist attacks in courts of law. Based on their findings, there have been several conflicting decisions made by the courts about how the definition of an occurrence is handled, depending on the type of loss and the line of business involved i.e. aviation, liability, property etc. In some cases, the terrorist attack is treated as the common cause resulting in a single event and in others where separate aircraft took off from separate airports and hit separate buildings, the incident is treated as separate events, particularly in the aviation industry. As a result of these findings and many more indicating this case is not as clear cut as originally thought, my opinion changed from applauding Swiss Re for making a gutsy first move to taking a wait-and-see approach as to how this decision will impact Mr. Silverstein, the insurance industry and the rest of the claimants in New York City. Although there is case law for the handling of the definition of an occurrence in the event of a terrorist attack, there is no consistency across the courts, thereby making the decision of the US Federal Court in Manhattan very difficult indeed.

The way I concluded my amended column is as follows and this is what I still believe: "It's a dicey situation for everyone involved and one I'll be monitoring to see what becomes of Swiss Re's gutsy first move. I guess someone had to make the first move to bring resolution to this sensitive issue for the claimants, the city of New York and the insurance industry.

Writer's note: Because this is a developing case in a court of law, facts are emerging and changing at a constant rate. My opinion is based on information as of Friday, October 26, 2001."

Cathy Duffy is a Chartered Property Casualty Underwriter (CPCU) and is now a freelance writer. She is a former executive of Zurich Global Energy. She writes on insurance issues in The Royal Gazette every Monday.