Evidence collected at the site of April’s home explosion is now at a storage and testing facility in Gwinnett County, according to the Office of the Insurance Commissioner.

Glenn Allen, a spokesman for Insurance Commissioner John Oxendine, said investigators did not elaborate on when they would be finished testing the appliances, pieces of gas line, and other items taken from the Saddle Brook home.

“Right now, we have concerns, but they are more of a general nature,” said Allen. “We are not looking for anything specific and nothing has really changed.”

Earlier Calhoun Fire Department Deputy Chief Terry Mills said gas was the culprit in the April 15 explosion that leveled the home and displaced 18 families.

“We know it was gas; we have to figure out what caused it and what caused it to be so large,” said Mills.

In fire investigations, Mills explained, all accidental causes have to be ruled out before investigators look at intentional causes. If the investigative labs find evidence that the explosion was intentionally caused, they will turn the evidence over to the state crime lab for further investigation.

It could take the lab up to four weeks to complete the investigation, he said.

Excavation resumed last Tuesday after a month-long hiatus.

“There is so much damage and so many claims, that the seven or so insurance companies, the (state) fire marshal, and fire investigator all needed representatives on site,” said Mills. Also on site were representatives from the manufacturers of the gas appliances that were in the house.

Restoration crews worked Monday removing pieces of gas line and gas appliances, preparing them to send to a private investigation lab.

According to Mills, the insurance companies agreed to outsource the initial investigation and have hired PTC, a forensic consultation firm to help with that. The company coordinates with all the insurance investigators.

“Otherwise, the Calhoun Fire Department would have to pay for all of this, which would mean the residents of Calhoun would have to pay,” said Mills. “The insurance companies are bringing in these resources.”

Mills wouldn’t venture on how much the contractors costs, but said private sector pays significantly higher than their government counterparts. The goal now, he said, is to determine why the explosion was so large. Early estimates indicate about $6 million in damages to the Saddle Brook community. About 18 families were displaced due to damage caused by the April 15 explosion.

Homes around the excavation site still bear the scars of the explosion. Windows and doors remain boarded up, gutters hang off exclusive, million-dollar homes.

Mills said security continues to monitor the site around the clock.

Previous stories:

Calhoun explosion being investigated as accident, officials say

Atlanta Gas Light Company says explosion not related to outside lines

Alcohol Tobacco and Firearms division brought in to inspect explosion site