Mundey said fire crews did not learn until about 5:30 a.m. that the man who lived at the house was not inside.
Maryland State Police made calls and confirmed that the owner was at work, he said.
The homeowner bought the house about six months ago, Mundey said.
Mundey said that the cause of the fire was being investigated. He said he was not sure in which room the fire started because "it was already fully involved with fire by the time we got there."
"The interior floor gave way to the basement and everything else pretty much fell down around it," he said. "The home was completely destroyed."
The blaze caused power problems in the surrounding area, Mundey said.
At least 76 Allegheny Power customers lost electricity because the fire burned a power line, company spokeswoman Janice Lantz said. She said later that power was restored to all of the affected customers at about 10 a.m.
One customer, WHAG-TV, has a communications tower nearby. The television station, known as NBC 25, was temporarily knocked off the air.
Washington County's emergency communications system also was briefly affected.
A dispatcher said the county has an antenna on a tower there. The system immediately switched to backup power.
Fire companies from Clear Spring, Williamsport, Fairplay, Morgan County, W.Va., Maugansville, Halfway, Hancock, Longmeadow and Mercersburg, Pa., helped put out the fire, he said.
The fire was under control within about 45 minutes of the fire companies' arrival, he said.
