Dr. Diane Barnett, Lucas County deputy coroner, said Mr. Fleming died of smoke inhalation. Test results on carbon monoxide levels were pending, she said.
No other injuries were found except for those caused by the excavator used to remove the rubble and from pressure of the debris on the body, she said.
A ruling on whether the death was accidental or a homicide was awaiting the investigation into how the fire began, she said.
The fire was reported at 3:45 a.m. Friday and four children, ranging in ages 3 to 9, were rescued from the second floor of the 12-unit building. City crews began demolishing the building Friday.
Family members had contacted the department around 4:30 p.m. Friday regarding a missing family member, but darkness prevented a further search of the destroyed building, fire officials said. The search resumed Saturday morning; officials discovered Mr. Fleming’s body Saturday afternoon after about a six-hour search.
Mr. Fleming lived in the unit alone, and his children, ages 1, 2, and 3, were not there during the fire.