A blaze that damaged a vacant York City row home on Tuesday night has been ruled arson, York City Fire Chief David Michaels said.

"We really have no other reason the fire would have started," he said, because there were no utilities turned on at the house.

Firefighters were called to a house in the 100 block of West King Street just after 9 p.m. and found flames pushing out of the first-floor front window, fire officials said.

The blaze was extinguished quickly and primarily contained to a front room, although there was some extension to a second room, Deputy Fire Chief Greg Halpin said at the scene. The house also sustained smoke and water damage, he said.

Damage is estimated at $10,000, according to Michaels.

"We believe someone was in there," he said -- maybe as a squatter, maybe as a trespasser.

Anyone with information about the fire can call York City Police at (717) 846-1234.