NTSB Preliminary Report Finds Gas Leak Preceded Consecutive San Antonio House Explosions

Federal investigators confirm a localized line break occurred 46 minutes before a secondary blast leveled a second North Side residence.

Federal safety regulators have traced the source of the two home explosion that rocked a North Side San Antonio neighborhood last month to an underground natural gas pipeline. According to a preliminary report issued by the National Transportation Safety Board (NTSB), utility personnel officially identified a significant underground gas leak nearly an hour and a half before a secondary explosion destroyed a nearby property on Preston Hollow Drive.

The sequential blasts, which occurred on Tuesday, April 21, completely leveled two structures. The force of the detonations sent shockwaves across the 15000 block of Preston Hollow Drive, hospitalizing five neighborhood residents and an on-site utility field technician. The emergency response quickly shifted into a complex federal safety probe as investigators zeroed in on a neighborhood distribution system featuring a two-inch diameter high-density polyethylene primary main and one-inch connection service lines, which were originally laid in 1993.

Timeline of the Preston Hollow Blasts

The disaster developed in distinct operational windows on April 21. At 6:04 PM, the first residence experienced a fuel-gas explosion that destroyed the building's frame and severely injured three family members inside. Timothy Nowell, Kimberly Nowell, and their teenage daughter all sustained serious burn injuries in the initial blast. Responding crews from the San Antonio Fire Department managed to establish control over the structural blaze within minutes, clearing the way for CPS Energy personnel to arrive on the property at approximately 6:32 PM to evaluate the localized grid infrastructure.

By 6:50 PM, a responding utility worker utilized field instruments to identify an active underground gas leak traveling through a service line. However, at 8:25 PM, as crews continued to survey the immediate perimeter, the home sitting two doors away suddenly detonated. This secondary explosion trapped and severely injured two additional occupants, Jose Ochoa and Mayte Terrie Reeves, while also injuring a nearby CPS Energy employee. In total, the disaster left six individuals injured, three of whom remain listed in critical condition at regional trauma centers.

"The NTSB report highlights that while the second home destroyed by the blast wave did not actively maintain natural gas utility service, the leaking pipeline run was situated directly adjacent to the property infrastructure."

Analysis of Materials and Planned Actions

Subsurface soil sampling executed the morning following the incident confirmed that substantial amounts of escaped gas remained trapped within the localized subsoil layer near the foundations. However, sweeping checks across the broader subdivision revealed no additional pipeline breaches or drop-offs in network operating pressures, indicating the failure was isolated to that specific line segment.

Emergency crews successfully isolated the broken distribution main and permanently plugged the service connection at 1:40 AM on April 22. The NTSB confirmed that the fractured section of the one-inch service line and an adjoining portion of the primary gas main have been extracted and shipped directly to its forensic lab facilities for microscopic material testing. While litigation has commenced on behalf of multiple impacted families, federal investigators noted that a finalized determination of probable cause will require a comprehensive evaluation lasting 12 to 24 months.