Chantilly — One minute, Thuan Nguyen and his family lived in a two-story house in Chantilly’s Brookfield community. The next minute, it was gone — blown sky high in a gas explosion and burned to the ground.

It was Dec. 19, 2010 and, luckily, the family was out with friends when their home and everything in it was destroyed. Since then, the Nguyens have built a new home on the same site and hope to move in soon.

But members of the community still have a nagging feeling of unease because, although more than a year has passed since the explosion, they still don’t know for sure what caused it. However, things have been moving forward and the Virginia State Corporation Commission (SCC) issued its findings in a Nov. 30, 2011 report now being made public.

Brookfield Civic Association President Larry Leeds shared the results with the residents during a Jan. 19 homeowners meeting. "Washington Gas is still investigating," he said. "But the [SCC] found Washington Gas had several [probable] violations, including violations of its own operating procedures."

Not all Brookfield homes are serviced by gas, but Leeds told residents they can ask the local fire department to come to their homes and check them for leaks. It’s a free service and, said Leeds, "If I was living in a house heated by gas, I’d be concerned."

The incident occurred around 8:45 p.m., bringing some 60 firefighters from five stations — including two hazardous-materials units — to the scene. Just prior to the blast, neighbors who’d smelled gas began calling 911; but the house blew up while fire units were en route.

Shortly after the explosion, Washington Gas found and repaired a gas leak beneath the road outside the Nguyens’ home. "These people did lose their house, but they’re really lucky that they’re still alive," said Leeds. "There were a couple miracles, that night — one, that nobody got hurt; and two, that nobody got killed."

The Fairfax County Fire Marshal’s incident-summary report lists the value of the property as $260,810 and its contents as $130,405, for a total loss of $391,215. The report concluded that "this fire was accidental and, most likely, the result of a natural-gas release into the structure which accumulated from the top down to the first floor."

"Once the flammable gas and air mixture reached the ignition source — most probably the open-flame water heater located within the first-floor utility room — ignition occurred," the report continued. "[This resulted in a] rapid release of energy starting high and then exiting through the front of the house."

Since then, the SCC’s Division of Utility and Railroad Safety did a thorough investigation and concluded that Washington Gas — mostly referred to in the 41-page report as WGL, for Washington Gas Light Co. — committed 11 probable violations, both before and after the explosion.

According to the report, investigation revealed that "the gas service line to the home experienced severe corrosion that resulted in a major gas leak in the road in front of the home. In addition, a section of customer-owned, natural-gas fuel line terminating on the second floor of the home was discovered without an end cap."

The SCC further concluded that the exact cause of the explosion can’t be determined because of "1. The failure of Washington Gas Light Company to properly collect and document certain important information immediately after the accident relative to possible migration of natural gas, and 2. The absence of any evidence that the customer-owned, gas fuel line terminating on the second floor of the home was properly capped."

WGL filed a report with the SCC stating it couldn’t determine the cause, either. But as the result of its own findings, the SCC cited WGL for several probable violations of SCC Pipeline Safety Standards.

Among its findings, the SCC noted that:

• "The homeowner built two additions to the home and gave notice of the construction to Virginia’s notification center on April 1, 2008. WGL marked the service line to 4303 Lees Corner Road on April 3, 2008. The homeowner or his contractor did not request [WGL] to move the gas service line so it would not have been in conflict with the home addition. [And WGL] did not identify that the addition was being constructed over its gas service line and that the gas service line should be moved;
• The addition built in 2008 on the left side of the house was built on a concrete slab poured directly over WGL’s gas service line. The SCC therefore cited WGL for failing to monitor excavations over WGL facilities, as required by its own Operations and Maintenance Standard 4099.
• WGL performed a leak survey of its facilities in this area on June 1, 2009. No record was provided that demonstrated the service line to 4303 Lees Corner Road was surveyed for leaks under the house."
• Before the incident, residents in the vicinity of the home smelled gas and called 911. Upon arrival after the explosion, the Fire Department reported "bubbling" at the curb in front of the Nguyens’ house. It also measured and documented natural-gas levels inside nearby homes.
• However, according to the SCC report, "WGL did not document the initial combustible gas readings taken upon their arrival to the site. The only documented readings taken occurred after the leak on the service line to 4303 Lees Corner Road had been repaired.
• Based on the information from several residents in the area, and the Fire Department, gas was migrating from the leak on the service line. The Company did not fully identify the gas migration area. [So] the extent of the gas migration or its path [were] never determined."
• The report also stated that "WGL did not take any readings of combustible gas in the soil prior to beginning to aspirate to remove residual natural gas in the ground."

Furthermore, according to the SCC investigation report, "Severe corrosion created a number of holes in the natural-gas service line serving 4303 Lees Corner Road at the connection to the service tee on the steel main. The piping had been weakened to the extent that a portion of the service line broke off when it was removed from the ground. Natural gas would have been escaping from these holes at 55 [pounds per square inch]."

Centre View contacted WGL spokesman Ruben Rodriguez for comment and, on Monday, Jan. 30, received the following reply: "The homeowner’s insurer submitted a claim for damages and has laid the foundation for litigation. Therefore, we are precluded from discussing details."