Cleveland - An 89-year old woman is alive tonight – all because of her dog.
Instead of a smoke detector, it was her three year old Rottweiler that let her know that her house was on fire.
All that's left of the house is parts of its shell.
Investigators say the fire started in the walls and spread quickly to the second floor and out the roof.
Mary Keys had no idea until her Rottweiler – Zeus – kept running in and out of the house.
"I went to put him out this last time, he came back in the house and the fire was just shooting up behind the couch," said Mary.
Mary rushed to wake up her grandson.
They made it out safely – but wouldn't have without Zeus.
"I thank God we are alive, that's the most important thing. All of this is material. You can always get another house, another place to stay but the life, you don't get another one," said Mary.
Firefighters say pets can detect heat faster than humans.
Even though firefighters prefer smoke detectors, they're thrilled to have a little help saving lives when every second counts.
"The most important thing is your life and in this situation the dog needs to be treated very, very well shall we say," said Larry Gray with the Cleveland Fire Department.
As for Mary, even though she's lost the only house she's known since 1953, and everything inside, she's grateful that Zeus was watching over her and her grandson.
"Oh I'm so grateful. The Lord is good. That's my angel," said Mary.
Investigators don't know what caused the fire.