As Hurrricane Irene whirls northward, bringing a wave of evacuations and prompting frantic runs on grocery stores, insurance companies and business owners are bracing for the costs that could number in the billions of dollars.

Noting that the storm could sweep across as many as 65 million people, Time.com cites the company Kinetic Analysis Corp's estimate that Irene may cause $13.9 billion worth of damage, with another $6 billion or so lost because of idle workers and unshipped goods stranded by the storm.

Irene to Hit Densely-Poplulate Northeast U.S.

We're looking at a multibillion-dollar event; that's almost certain,  Bob Hartwig, president of the trade association Insurance Information Institute, told NPR. We're not looking at a hurricane that is as strong as a Katrina or a Hurricane Ike, but we are looking at a storm that will move over an area that has much greater population than an area like New Orleans or South Texas.

Katrina remains the hurricane by which modern American hurricanes are measured, and it caused an astonishing $133.8 billion in damages in addition to more than 1,800 fatalities. While Irene is not nearly as powerful as Katrina, particularly given its recent downgrade to a Category 1 storm, meteorologist Paul Yeager warns on the Huffington Post that the damage could still be substantial given the total terrain the storm will cover as it touches down.

Expensive Infrastructure

Between damage to infrastructure (buildings, boardwalks, mass transit systems, etc.), storm surge flood damage, fresh water flood damage (from heavy rain), beach erosion, and vehicular damage, it's possible that Hurricane Irene will be another billion-dollar-plus U.S. weather disaster, Yeager writes.

Hartwig made a similar point to NPR, noting that while individual buildings would likely suffer less extreme damage than in previous storms, the damage would be more widespread. That is likely causing some anxiety among insurers who are now anticipating a mountain of claims from potentially millions of homes and businesses.