DALLAS (CBSDFW.COM) – An early morning house fire in South Dallas left an elderly woman critically injured, her home destroyed and a dog and cat dead.

It was just before 2:00 a.m. Tuesday when Dallas Fire Rescue crews arrived at the home in the 2300 block of Metropolitan Avenue, near Highway 175. Heavy flames and smoke were already billowing from the front windows, but firefighters were able to get it under control quickly.

(credit: CBSDFW.COM)

Fire crews found an 87-year-old woman unconscious and lying in a hallway. The woman, whose name has not be released, was immediately taken outside where medics began life saving measures. Ultimately she was taken to Baylor Medical Center in critical condition. No word on if her injuries were from burns, smoke inhalation, or both.

Firefighters also found a dog and cat inside the home that did not survive.

Later Tuesday morning, investigators determined the fire started in a den area, in the front of the home. From there, flames made their way up the walls and into the attic space, destroying the entire room.

Investigators are still trying to determine exactly what sparked the fire.