A 44-year-old man was killed early Sunday after fire broke out in a home near Grayslake, authorities said.

The fire was reported shortly before 12:40 a.m. at a residence in the in the 17800 block of West Winnebago Drive.

According to Lake County sheriff’s police, deputies called to the scene met outside with the home’s owner, who had escaped the fire but reported that her son was still inside and trying to get out.

Deputies attempted to go into the home, but the smoke was too heavy and they were unable to enter, sheriff’s police said.

Gurnee firefighters arrived a short time later and were able to enter the home with their protective gear, officials said. They located the man unconscious and not breathing. Lifesaving measures were started, and the man was transported to an area hospital, where he later was pronounced dead, sheriff’s police said.

The Lake County Coroner’s Office will conduct an autopsy, sheriff’s police said.

Sheriff’s detectives, fire officials and the Illinois State Fire Marshal’s Office are investigating the cause of the fire, but preliminary indications are that it is not suspicious, authorities said.