BEAUMONT, Texas -- Residential and commercial insurance claims could total $4 billion to $10 billion. More than a million customers, including some refineries, lack electricity. And retailers are gearing up for a burst of sales once residents who fled the Gulf Coast return.

Snapshots of Hurricane Gustav's economic impact revealed Tuesday that the storm was hardly as damaging as feared -- particularly for the region's vast network of energy facilities. But it will be days, if not weeks, before business as usual returns.

While Gustav's force paled in comparison to Hurricane Katrina, which cost insurers $41 billion, oil workers, utility crews, fishermen and other business owners fanned out across the Gulf Coast Tuesday to assess damage and make preparations to restart operations.

Outside a Lowe's in Houma, La., 34-year-old sales manager Britt Coyle said there was only minor damage to the store, which he expected to be open on Wednesday to sell chainsaws, generators and other necessities to residents returning home.

For the moment, there were no customers in sight, and power outages in the area were widespread.

At the nearby Jolly Inn restaurant, the owners had a diesel generator powering their refrigerator in order to prevent thousands of dollars worth of food from spoiling. Forty-five-year-old Denise Prosperie-Fritch, whose family owns the Jolly Inn and rode out Gustav inside the restaurant, said the establishment is insured but that they only have one or two days worth of diesel fuel left to keep the food cold.

"We will be addressing our hardest-hit policyholders first," Elizabeth Stelzer, a spokeswoman for Nationwide Mutual Insurance Co., said. "Those homes with a tree through a wall, an exposed roof, or other claims in which the home has become uninhabitable are the priority."

Meanwhile, utilities started dealing with the task of restoring power. Utility giant Entergy Corp. said 826,000 customers, mostly in Louisiana, were without power. A Royal Dutch Shell-owned refinery in Convent lacked power late Tuesday, as did the company's chemical plant in Geismar. The power outages also brought down cellular and Internet service in parts of Louisiana.

Entergy did not have an estimate on when power may be restored, saying it could be weeks in some instances. "Our transmission system has had massive damage," Entergy spokesman Mike Burns said, noting damage to 191 transmission lines and 210 substations that affected 825,000 customers, mostly in Louisiana.