Three people are dead after an early morning fire broke out in Prince William County, Virginia, on Friday.

It happened before 6 a.m. at the 15700 block of Piedmont Place in the Montclair area.

When firefighters arrived, the two-story house was engulfed in flames, the Prince William County Department of Fire and Rescue said.

There was a family of three who lived in a basement apartment of the house. They were able to escape the burning home.

Three people were unaccounted for when firefighters arrived. They then found three people dead inside the house after the fire was extinguished.

The Prince William County police later identified the deceased as Sameena Begum, 49, a 13-year-old boy, and an 8-year-old boy. The two boys were her sons. The father was at work when the fire happened.

Officials said that due to the extent of their injuries, the medical examiner’s office will conduct autopsies to determine the cause of death, but they don’t appear to be suspicious.

The cause of the fire remains unknown, but because of the severity, the Bureau of Alcohol, Tobacco, Firearms and Explosives will be helping the Prince William County Fire Department investigate.