Dallas, TX – When the house 9430 Eloise Street in Dallas exploded last March with two people inside, no one really knew exactly why… until now.

WFAA has learned the explosion traces back to a faulty compression coupling, the kind that we discovered were responsible for fatal house explosions all over North Texas.

The kind that state regulators proposed be totally removed from the ground in Texas beginning in 2010.

A removal that we now know never took place.

But first, the explosion on March 2, 2015. That’s the day a wood frame house in the Pleasant Grove section of Dallas blew up without warning.

Two people inside — 77-year-old Rosetta Clark and her grandson, 39-year-old Juan Young Clark — somehow survived the blast and the collapse before digging their way out of the debris.

“Mr. Clark found himself buried under mounds of wooden structure of the home,” said family attorney Stephen Pipkin.“He literally had to crawl in darkness wondering if he was going to survive.”

While Clark and his grandmother are still recovering, they were never told what caused the explosion.

Until now.

According to investigators with the Texas Railroad Commission, gas leaked into the Clarks’ home from acompression coupling just a few feet away in the street. It’s the same kind of coupling being blamed for dozens of injuries and deaths across the country over the past two decades.

Faulty compression couplings were the focus of a three-year WFAA investigation following fatal house explosions across North Texas. Atmos Energy has been sued, and has settled with numerous victims and their families. The gas company has voluntarily removed thousands of couplings from high-risk areas.

But it’s now clear that an untold number of couplings remain in the ground.

In January 2010, Atmos was called to a house at 9426 Eloise Street; someone had smelled gas. Workers later unearthed a leaking coupling out front.

Five years later, the house next door exploded. The cause: A leaking coupling.

It’s the same type of coupling linked to previous natural gas explosions, some of which were fatal.

“It’s grossly negligent, in our opinion, on the part of Atmos,” Pipkin said. “It’s a lack of caring of something that could have been done, and the system could have been expedited to assist people like the Clarks, including their neighborhood. It just didn’t have to happen.”

Yet despite pledges by state regulatory officials in 2010 to force the statewide removal of all of the faulty couplings, the full removal order was never issued. The 64-year-old leaking coupling that led to the destruction of the Clarks’ home was allowed to remain in the ground.

The Texas Railroad Commission issued notice of violation to Atmos last month in connection with the March explosion.

On September 4, the Railroad Commission dismissed the violation, saying any problems had been corrected.

Atmos has declined to comment.