Evaluating Procedures in Deadly NJ Blast

Watch this raw video of a mother running with her two children to safety moments after the gas explosion in Ewing Township. (Published Thursday, July 17, 2014)

As the investigation of a deadly explosion in Mercer County, N.J. goes into full swing, one of the things authorities will evaluate is the procedures crews followed at the scene.

"The person that was operating down there felt that they had struck something," Ron Lunetta, a lieutenant with the Ewing Township Police, said during a news conference. "At that point, they retreated and tried to make contact with their people and also public service."

Viewer Josh Frost sent NBC10 this cell phone video of the gas explosion in Ewing Twp. (Published Thursday, July 17, 2014)

Whenever any work disturbs the soil, New Jersey state law requires the excavator to notify the New Jersey One Call center at 811 or 1-800-272-1000 at least three full business days prior to breaking ground.

The three-day period allows the utility companies to send their own crew or a third party contractor to the job site to indicate with paint, flags or stakes where the utility lines are located.

Once marked, the excavator has an eight to 11 day window to start the project by hand digging within 2-feet of either side of the indicators.

When tools hit the ground Tuesday, something went wrong.

NBC10's Na'eem Douglas was one of the first reporters on the scene of a gas line explosion that destroyed one home and damaged others. The explosion also injured seven people. (Published Thursday, July 17, 2014)

The explosion, which killed one woman and injured seven others, happened about 12:50 p.m. while workers were trying to repair a gas line at 28 Crockett Lane inside the South Fork development in Ewing Township.

According to PSE&G, one of their contract workers, who was replacing electrical service at that unit, had damaged a gas line and according to PSE&G Director Mike Gaffney, "the damage caused a leak."

"If you accidentally damage gas piping or smell gas when excavating, please call 911 immediately," reads PSE&G's website. "Then, call 1-800-436-7734."

During the news conference, Lt. Lunetta said the Ewing Police Department received the first call about the explosion around 12:51 p.m.

It is unclear if police were informed of a damaged gas line ahead of the initial blast reports. Gaffney said PSE&G was notified at approximately 11:45 a.m., "and at approximately 11:58 we had a crew respond to the scene, to an odor in the air. We are in the process of investigating how that damage did happen to our facilities and as soon as we do come to a conclusion, we will report that as quickly as possible."

After notifying authorities and the gas company, PSE&G suggests authorities secure the area and evacuate as needed, check near-by buildings for other possible leaks, eliminate sources of ignition, and stay upwind of leaks and away from manholes and other possible gas outlets, according to its website.

PSE&G workers were standing in front of the Crockett Lane home to investigate and repair the damage when the explosion occurred.

"The gas main did not explode. We are investigating right now what the source of the ignition was and what actually ignited," said Gaffney.

If other utility lines are struck, the excavator must notify the appropriate company and New Jersey One that a line may have been uncovered or damaged.

Authorities are working to determine the cause of the deadly blast.