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OKLAHOMA CITY - Last weekend, an Oklahoma City neighborhood was stunned when a house suddenly exploded early Saturday morning.

In all, three people were injured in the explosion and dozens of homes were damaged in the neighborhood, located near N.W. 122nd St. and Rockwell Ave.

Initially, fire investigators said it was obvious that natural gas found its way to an ignition source inside the home, which led to the explosion.

However, an exact cause was not available.

On Wednesday, officials with the Oklahoma Natural Gas Company released the preliminary results of their investigation.

"Preliminary results indicate that a leak occurred at a weld seam in a section of the gas main. Natural gas escaped from the main and migrated underground where it entered the residence. The gas was then ignited by an unknown source," a release by ONG read.

“Why did that weld separate? That’s the root cause,” said Matt Skinner, spokesperson for the Oklahoma Corporation Commission.

Skinner says their Pipeline Safety Department will be working with ONG to determine just that, the root cause.

ONG says that natural gas escaped from the main and migrated underground where it entered the home. The gas was then ignited by some unknown source.

“The inspector’s job is to make sure that, in this case, the utility has the testing done in a manner prescribed by protocol and by law,” said Skinner.

Skinner says an independent lab will do the testing on the weld that failed. He says it was a four-inch poly line, so it wouldn’t have rusted.

They will also be looking into the issue of a sewer line out at the property.

“Apparently, at the scene, there are indications that the sewer line was somehow compromised. So part of this investigation will be to determine how did that happen, when did it happen, was it in any way related to this incident,” said Skinner.

The segment of the pipe will continue to be tested to determine what caused the separation.

There are also reports that residents in the neighborhood smelled gas for several days before the explosion.

“That’s one of the things that the investigator is looking at,” said Skinner.

ONG says the segment of pipe involved has been removed and preserved for further examination and that the gas main has been repaired and is safely back in service to the unaffected households.

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