EARLINGTON, Ky. (AP) _ Fire swept through a three-story apartment building before dawn Tuesday, collapsing the top two floors and leaving three residents unaccounted for and believed dead.

Nearby rail service was halted out of fear that the three walls left standing might collapse from the vibration.

``A heavy wind could come along and cause it to tumble,'' coroner John Walters said.

Authorities did not know how the fire started at the Victory Apartments in this small community in western Kentucky.

``It's fair to say we don't have any suspicions,'' said Steve Spies, a spokesman for the federal Bureau of Alcohol, Tobacco and Firearms, which was called in because the building's first floor contained a post office.

Diane Rhye, the owner's step-daughter, said Tuesday that at least three of the eight tenants were unaccounted for, including two newlyweds who lived there about a year.

A law officer among the first to arrive saw a body hanging out a broken window on one of the upper floors moments before the building collapsed.

``He realized that person had probably already died,'' said Walters. ``When the floors collapsed, that all went down to the bottom.''

State Police spokesman Bryan Pitney said three adults escaped and were treated at a hospital and released.

It could take as long as three days to retrieve the bodies because of the rubble and because the brick building, built in 1903, had retained so much heat from the intense blaze.

``It's going to be hot for quite a while,'' Pitney said.