Investigators confirm to Channel 2 Action News there was not a single working smoke detector inside the home where four children died in a fire, but they have not determined what started the blaze.

"We know that upstairs, there's no evidence of a smoke detector," said Rockdale County Fire and Rescue spokesman Michael Morris.  "We did find one downstairs, however, it was inoperable."

Morris said the downstairs smoke detector did not have a battery inside, but officials could not tell if that was a violation of county code.  They confirm the blaze appears to have started in an upstairs hallway near the bathroom.

The fire gutted the Pinedale Circle home in Conyers Tuesday night.  When she discovered the fire, Reba Glass tossed her 6-year-old son Darnell Junior out a second story window, then jumped herself. 

After rescuing her mother asleep downstairs, officials said, Glass tried to rush back up the stairs to rescue her other children but suffered second- and third-degree burns over 40 percent of her body in the failed attempt. 

Ah'Dariya, 9, DeShawn, 7, Amoni, 3 and 8-month-old Deon Jr. died in the fire.

Darnell Jr. was treated and released from Children's Healthcare of Atlanta at Eggleston, but Glass remains in Grady Hospital's burn unit.

"Lots of pain," said family pastor Billie Cox, describing Reba Glass' injuries.  "She has burns on both arms, her right leg, stomach, back and on her forehead."

Cox visited Glass in the hospital Thursday morning.  She said Glass was in good spirits but was devastated by her loss.

"Emotionally? I think I'm going to say indescribable because I just can't even imagine being able to find a descriptive (word) that would categorize what she must be feeling at this moment," said Cox.

Cox is holding a prayer service for the family at the Macedonia Baptist Church in Conyers Thursday night.

A memorial fund was set up at Wells Fargo Bank, and donations can be made at any bank in the name of the Glass family. A Facebook page is also soliciting donations.