Officials identified the victim as Jacqueline Truss, the widow of retired long-time police officer George Truss.
Surveillance video from across the street reveals how the fire started in a container in the backyard right around 1:30 a.m. Monday.
The flames then quickly spread to the home on the 1500 block of Division Street.
Jim Bessing, who lives across the street, says he was awake when the fire started. He said he quickly ran to the home and started pounding on the front door to alert his long-time friend and neighbor inside.
"That's when Joe across the street came over and then grabbed a big rock from the garden, threw it through the window, but when he did black smoke came out of the window. By that time it was just raining fire on us," Bessing said.
Investigators say members of Jackie Truss' family were at the home on Sunday cleaning up the backyard.
Police believe those family members burned dead wood and fallen leaves in a metal drum a short distance from the home.
"Obviously, it wasn't fully extinguished at that point. No one thought anything of it but there was absolutely still something hot cooking in there," said West Deptford Police Chief Sean McKenna.
Investigators have since deemed this fire a tragic accident.
One firefighter was taken to the hospital with injuries.