A 71-year-old man died in a house fire in Lilburn after one person was found injured, the Gwinnett County Fire Department said.

The fire happened at a home Saturday on James Street about 10:30 a.m., Gwinnett fire chief Tommy Rutledge said.

Someone reported smoke coming from the home and two parked cars in the driveway, Rutledge said. Firefighters knocked on the door, but got no response.

Fire crews went inside the single-story home through the basement and found an unconscious man on the main level.

He was taken to Gwinnett Medical Center where he died with life-threatening injuries, Rutledge said. His identity was not known.

The man’s wife was not home at the time of the fire. No other injuries were reported.

Rutledge said they have no idea how the fire started. The investigation is ongoing.