(BERLIN TOWNSHIP) -- Authorities say a woman has died following a house fire in St. Clair County. The sheriff's department says crews responding to the home in Berlin Township on Friday morning found it fully engulfed in flames. Investigators say three people inside the house at the time that the fire started escaped uninjured, but the woman wasn't able to get out. Several area departments responded to the blaze. The woman's identity wasn't immediately released. The cause of the fire is under investigation.