BERLIN TWP. (WWJ) - Authorities say a St. Clair County woman is dead following a house fire Friday morning.

The sheriff’s department says the fire started sometime before 4 a.m. at a home on Lathrop Road in Berlin Township, just north of the Macomb County line. When crews arrived on the scene, the home was completely engulfed in flames.

Fire officials determined there were four people in the house when the fire started. Three people made it out of the home uninjured, while one woman was unable to escape. The woman, whose identity was not immediately released, was declared dead at the scene.

Firefighters said the fire was extinguished just before 6 a.m., although the cause of the fire is currently unknown.

An investigation is ongoing.