Kentucky State Police were investigating Friday morning a deadly house fire that left four people dead in Casey County, according to the Herald-Leader’s reporting partner, WKYT.

The fire happened at the intersection of Kentucky Highway 70 and 837, according to WKYT. The house was fully engulfed with flames and firefighters battled the fire for at least five hours. Fire departments from around the region responded to help.

The names of the victims have not been released as of Friday morning. WKYT reported that the Kentucky State Police were leading the investigation.

It’s unknown what caused the fire.

This is a developing story and will be updated.