Before the Sept. 11 attacks in 2011, terrorism was such an afterthought to most insurers that they didn’t bother to mention it in most property and casualty policies. They were essentially providing the coverage for free. As this weekend’s incidents in the New York City area and in St. Cloud, Minnesota, prove, this is a risk companies and people can’t afford to ignore. Indeed, terrorism insurance has become a cost of doing business for companies ranging in size from Fortune 500 giants to mom-and-pop corner markets. Individuals are increasingly interested in the coverage as well.