The Fulton County Medical Examiner's office Friday identified a man who died Thursday in a predawn fire in Roswell as Thomas Johnson, 68, of Roswell.

The Spring Drive home was fully engulfed when firefighters arrived shortly before 4 a.m., Roswell fire Deputy Chief Paul Piccirilli said.

The top level of the home collapsed into the basement, and firefighters were sifting through debris with heavy machinery when Johnson’s body was located.

Investigators have not determined a cause for the fire, which destroyed the home.