Photo taken by DeKalb County Fire and Rescue of an April 12 house fire in Avondale Estates.

This story was updated on May 29.

DeKalb County Fire investigators have said they were unable to determine the cause of an April 12 house fire that killed a mother and her daughter in Avondale Estates.

The cause of the fire has officially been classified as, “undetermined” spokesman Capt. Eric Jackson said. He said he case is officially closed.

“With this one, they just couldn’t determine just what the cause was,” Jackson said. “And it’s not uncommon for that to happen.”

Tami Willadsen 43, and her daughter, Jess, 10, died in the April 12 fire on Lakeshore Drive. Her son, Jack, 5, was severely burned and his father, Dave, also received injuries.

There were clues pointing to a potential cause in an Avondale Estates Police reports about the incident. One of the witnesses told an officer that candles had possibly been left lit on the front porch. A few days after the fire, Jackson said the structure was engulfed in flames when the fire trucks arrived, making a rescue attempt impossible. Jackson said for the fire to have totally engulfed the 5,624 square foot home it would’ve needed a head start on the firefighters.

The Willadsens had just moved into the home and there was a gathering there on the night of the fire. A witness told an officer that guests were in the backroom of the home “when the fire suddenly started from the front of the house and quickly spread to the rear.”

Jackson said causes of fires generally fall into four categories: Intentional (which was officially ruled out in this case), accidental, natural and undetermined.

Jackson said investigators explored the possibility that a lit candle started the fire.

“They investigated that. They looked into that,” he said. “Based upon what they were able to get, they weren’t able to pinpoint absolutely with any certainty that is what actually caused the fire. They looked into it as much as they possibly could to see if they could determine a definite cause.”

Jackson said he wasn’t sure if the case would the case could be reopened if new evidence becomes available.

“Frankly speaking, because of the way the fire happened and because of the individuals that had initially given statements, we’d like to think that we captured everybody who might’ve seen or heard anything,” he said.