UPDATE: A Sunday night house fire in Athens claimed the life of an elderly woman.

Fifteen Athens firefighters responded to the home on Woodward Avenue about 6:00 pm Sunday, and were met with heavy smoke visible from the second floor.

That's when firefighters performed a search and rescue operation for the female victim still inside.

An Athens Fire Department Captain was told by a man who lived on the first floor about the woman inside who lived on the second floor. He told firefighters that he tried to rescue the woman but was unsuccessful because of the intense heat and being overcome by smoke. He also described the woman as bed-ridden and unable to walk.

An explosion inside the building during the fire knocked down two firefighters, but they were able to exit the building by themselves. Both firefighters were checked and later transported via fire unit to a local hospital for further evaluation.

Firefighters later discovered the woman's body.

The Tennessee Bomb and Arson Unit was called in to assist with the investigation. The investigation and the cause is yet to be determined but appears to be accidental in nature. AFD suspects the cause of the explosion to be linked to the use of medical oxygen by the occupant.

PREVIOUS STORY: An elderly woman has died following a house fire in Athens, Tennessee.

McMinn County dispatchers said the fire broke out around 6:00 p.m. on Woodward Ave.

As firefighters entered the home, there was an explosion believed to be caused by an oxygen tank. Two of them were taken to the hospital.

They've been checked out and are okay. 

The cause of the fire appears to be accidental, but it is still under investigation.

The house was severely damaged.

Stay with WRCBtv.com for more details on this developing story.