BEAUMONT, Texas — Residential and commercial insurance claims could total $4 billion to $10 billion. More than a million customers, including some refineries, have no electricity. And retailers are gearing up for a burst of sales once residents who fled the Gulf Coast return.

Snapshots yesterday of Hurricane Gustav's economic impact revealed 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 businesses' staff fanned out across the Gulf Coast yesterday to assess damage and prepare 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 today 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 to prevent thousands of dollars worth of food from spoiling. Denise Prosperie-Fritch, 45, whose family owns the Jolly Inn and rode out Gustav inside, said the restaurant is insured but that they only have enough diesel fuel left to keep the food cold for one or two days.

"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 yesterday, as did the company's chemical plant in Geismar. The power outages also cut 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.

Gustav also created problems for the region's Gulf Coast oyster industry.

Mike Voisin, owner of an oyster processing plant in Houma and president of the Louisiana Oyster Task Force, said Louisiana won't be producing oysters for at least a week to 10 days, depending on how quickly officials can ensure oyster beds have not been contaminated by floodwaters carrying bacteria. Similar closures were announced in Alabama and Mississippi.

Residential and land-based commercial losses, including costs of business interruption, were expected to total between $3 billion and $7 billion, Newark, Calif.-based Risk Management Solutions Inc. estimated. The firm estimated damage to oil platforms and wells, as well as production interruption caused by wind and waves, at about $1 billion to $3 billion.

Insurance industry analysts warned that computerized data on insurance losses may understate actual costs because the figure don't include damage to uninsured property or destruction by causes excluded from some policies, such as flooding.

Total losses won't be known for months.

Still, there were signs that the region held up better than expected: