Final answer:
The biggest loss for the insurance industry from the 9/11 attacks was due to property damage claims, exceeding other types of claims such as business interruption, liability, and workers' compensation.
Step-by-step explanation:
The September 11th attacks had significant financial impacts on various sectors, notably the insurance industry. The single largest source of loss for the insurance industry as a result of the 9/11 terrorist attacks on the Twin Towers was property damage. This included the destruction of the World Trade Center buildings themselves, as well as damage to surrounding structures and infrastructure.
In the wake of 9/11, the insurance industry faced substantial costs from various types of claims including business interruption, liability claims, and workers' compensation claims. However, the property damage claims were unparalleled due to the sheer scale of destruction wrought by the attacks.
These costs were far beyond the routine administrative expenses that insurance companies incur, such as hiring workers, administering accounts, and processing claims. The payments for claims, particularly for property damage, dwarfed the typical operational costs and premiums that insurance companies manage.