To be certified as a terrorist act, they must also assess whether insured damage, like building damage and lost income, exceeds $5 million.
If these officials don't certify the bombing as a terrorist act, the businesses' standard policy would apply.
Part of the definition for a terrorist act in the federal law states that the attack must have been "committed by an individual or individuals as part of an effort to coerce the civilian population of the United States or to influence the policy or affect the conduct of the United States Government by coercion."
The coverage itself is "relatively inexpensive," Hartwig says, but many factors influence the cost, such as location and the size of a business.
A small business in many cities might pay less than $100 a year for the coverage, said Hartwig.
"If you're a very large business with a lot of real estate, machinery, aircraft, or a stadium, these things will cost more of course," he said.