Insurance companies paid a total of 59.9 billion dollars in compensation related to the September 11, 2001 attacks. The attack created an enormous "wave" of simultaneous claims across multiple coverages, including property, business interruption, life, workers' compensation, liability, aviation, and event cancellation. The risk was redistributed through reinsurance, causing losses to cross borders and the balance sheets of insurance and reinsurance companies worldwide.
Larry Silverstein had leased the World Trade Center complex for 99 years just in July 2001, two weeks before the attacks. The claim generated an enormous legal dispute over whether the two planes that hit the Twin Towers constituted one or two occurrences. If they were considered two events, Silverstein could receive approximately 7.1 billion dollars, double the limit of approximately 3.55 billion. Swiss Re ended up being the biggest "victim" among reinsurers, with 778 million dollars in compensation, although it won the legal battle to be covered under the one-occurrence regime.
The attack caused 2,753 deaths, including 295 employees of broker Marsh & McLennan, 175 from AON, and 658 from bank Cantor Fitzgerald. Total compensation far exceeded payments to the dead and injured, with business interruption representing the most significant coverage. Event cancellation generated 1.8 billion dollars in payments, covering not only events at the WTC but also activities cancelled throughout the country due to airspace closure and fear of new attacks.
Before September 11, terrorism was often included in commercial policies without a specific premium. After the attacks, reinsurers reduced or withdrew capacity and insurers began introducing exclusions or substantially increasing prices. The United States created the Terrorism Risk Insurance Act (TRIA) in 2002, establishing a federal safety net for large terrorist events. Twenty-five years later, the sector faces a new threat: cyberterrorism, which can cause simultaneous losses in companies in different countries that depend on the same technology vendors, data centers, or cloud platforms.
