St. Louis County authorities have arrested a 24-year-old man after a baby boy was found dead inside a residence that caught fire Wednesday.

Flames were shooting out of a first-floor window and smoke was billowing out of a second-story window when firefighters arrived at a residence on the 800 block of N. 3rd Street in Tower at about 7:40 a.m. When the fire was put out, the body of Bentley Joe Lewis Koski was found inside the burned-out home, said Sgt. Steve Borchers of the Sheriff’s Office.

Investigators are still trying to determine what caused the fire but on Thursday said it did not appear to be a case of arson.

Sheriff’s deputies took the man into custody pending likely charges of second-degree manslaughter, child neglect, auto theft, possession of a controlled substance and possession of narcotic paraphernalia. He is being held in the St. Louis County jail in Virginia, Borchers said.