The Boston Marathon attack has sent shockwaves through the sports event insurance industry creating a lot of uncertainty about whether certain event coverages will be offered and at what limits. At a minimum, terrorism premiums for high risk events are expected to skyrocket.
Underwriters responded after the Sept. 11, 2001 terrorist attack with enhanced risk management for arenas and stadiums. However, closed venues are much easier to secure as opposed to an open event such as a marathon that has a 26.2 mile course.
Also, as a result of Sept. 11, 2001, private insurance carriers started to exclude terrorism coverage under General Liability policies, which was picked up by the federal government for a buyback of less than 5% of private insurance premiums in most cases. After 9-11, the terrorism coverage buyback was typically only purchased by larger event promoters in major population centers. However, as a result of the Boston attack, it is speculated that the terrorism buyback will become much more expensive and many smaller event promoters outside of the major population centers will be interested in its purchase.
The next question is what type of liability that event promoters and organizers have in the first place to prevent terrorist attacks? At first glance, event security against terrorist attacks would primarily be a matter for law enforcement. However, event promoters and organizers can have liability for not implementing risk management controls and coordinating with law enforcement. The industry will undoubtedly respond with enhanced risk management requirements based on the lessons learned from the Boston attack.
Source:  Boston Attack Leads Sports-Event Insurers To Reassess Business; Aaron Kuriloff and Mason Levinson,  April 17, 2013