Fire investigators will return Thursday to comb through the charred remains of Matty's Wayside Inn in Glenview after a two-alarm fire consumed the building early Wednesday.

The cause of the fire is undetermined. As of late Wednesday, investigators don't suspect arson, said Lt. Joe Faehndrick of the Glenview Fire Department.

A demolition company is expected to shore up part of the building so investigators can get in there safely, he said.

It could be a week before there's any indication of what caused the blaze. Fire officials likely will be turning the investigation over to the owners' insurance company, Faehndrick added.

He said a neighbor of the establishment called the fire department at 3:45 a.m. Wednesday to say he saw smoke coming from the popular restaurant on the 1700 block of Waukegan Road.

Upon arrival, the eatery was engulfed in flames, Faehndrick said, and a second alarm was called to bring additional units from surrounding departments.

"It became a surround-and-drown type of situation where the fire was so heavy and thick that we couldn't attack it inside," he said. "The fire kept rearing up because of the heavy timbers used to build the restaurant many years ago."

He said there were no injuries in the fire and the restaurant was empty when the blaze ignited.

The cost of damages is unclear at this time. The building was completely destroyed.

Waukegan Road was closed between Lake Street and Chestnut, authorities said, while firefighters battled the blaze.

Crews from communities including Winnetka, Niles, Deerfield, Wilmette, Morton Grove and Northbrook assisted in dousing the stubborn fire.

According to the restaurant's Web site at mattyswayside.com, the establishment has been open for about 80 years.

The book "Images of America: Glenview" by Beverly Roberts Dawson says the building was constructed in 1890 as a farmhouse, and opened as a restaurant at the end of Prohibition in 1931. Matty's started out as a restaurant that served liquor illegally during Prohibition, the book added.

• Staff Writer Madhu Krishnamurthy contributed to this report.