Wayne, Mich. - In an area challenged by one of the nation's toughest economies, any family business keeping its doors open is a success. In the working-class Detroit suburb of Wayne, the high-end William C. Franks Furniture store stood out.

A suspected natural gas explosion Wednesday morning leveled the 50-year-old business, critically injuring the owner, Paul Franks, and killing two employees, salesman James Zell, 64, and clerical worker Leslie Machniak, 54.

The blast destroyed "one of the anchor businesses in the town of Wayne for years," said Mayor Pro-Tem Donna McEachern, who has known Paul Franks for more than three decades. "This is one less very important business we have in the community."

Franks' father founded the store in the city of 19,000 about 15 miles from Detroit, and McEachern said the blow to the business community comes as the city mourns the deaths of Franks' employees and prays for his recovery. Franks, a staple in the community, was in critical condition Thursday in the burn unit at the University of Michigan medical center in Ann Arbor.

Utility and fire officials focused Thursday on determining whether a natural gas explosion leveled the store.

Consumers Energy spokeswoman Debra Dodd said crews worked overnight to repair a gas main behind what had been the Franks Furniture store and removed a section of pipe for investigation.

She said it was not clear if the main was damaged in the explosion or if it had been ruptured prior to the massive blast. An investigation into the cause could take weeks, if not months, she said.

"Nobody wants to jump to any conclusions," she said, but added, there are "things about it that are characteristic" of a natural gas blast.