It took close to 90 minutes to knock down the fire, Lewis said.
According to the press release, "A faulty fan motor in a cooler unit caused an electrical fire which ignited flooring."
The press release also states the building sustained "considerable smoke and heat damage," and the first floor and basement sustained fire and water damage.
Damage estimates were evaluated at $300,000, according to the release.
Surveying the damage Friday morning, restaurant owner Dan Aufdem-Brinke said, "Right now, it's like a dream. It's not real."
The 34-year-old Keedysville man has owned the restaurant for the past four years.
Just a few feet from Aufdem-Brinke, the restaurant's booths sat awkwardly on the brick sidewalk, their napkin dispensers still in place on the tables' edges. About 8 a.m., firefighters walked through the blackened first-floor of the restaurant, their reflective outfits barely visible.
An occasional flash of light revealed a firefighter scanning the walls and floors with a flashlight.
The restaurant's once bright orange awnings were tinged with soot, but still proclaimed the business' opening date of 1981.
Aufdem-Brinke said the restaurant draws a mix of people, and often brings in hundreds of patrons on weekends.
"It's devastating," said Boonsboro Town Manager Debra Smith, who stood across the street from the restaurant Friday morning along with local business owners. "We're in the process of trying to work with businesses to revitalize downtown, so this is really a step back."
In December 2005, a fire damaged the former Boone Hotel, which sits directly across the street from Asaro's, Smith said.
According to the fire marshal's release, Glausier's building was built in the 1840s. The town was founded in 1792, Smith said.
North Main Street was lined with firetrucks and hoses Friday morning. School buses and vehicles snaked through narrow alleys to navigate around the operation.
Across the street from Asaro's, Nora Beall, 39, said that in the middle of the night, she smelled smoke through the radiators to her 13 N. Main St. apartment.
"My cat woke me up," she said.
Beall said she cannot get cell phone service inside her apartment because of tin roofs in the area, but text messaged everyone she knew who was connected to the restaurant to tell them of the blaze.
"It's just surreal," she said. "It's something you see on TV, not across from my apartment."
Julie Barr-Strasburg, executive director of the Washington County Chapter of the American Red Cross, said the local chapter offered assistance and counseling to the Glausiers.
She said community members offered to board up the windows to the building for the couple, who are staying with family.
"They had people there with them since early (Friday) morning," Barr-Strasburg said.