The 1976 gas main under 3200 West: what the federal record says about the South Jordan explosion

The National Transportation Safety Board has closed its investigation into the November 2024 explosion that destroyed a home in South Jordan and killed the resident inside it, concluding that a crack in a plastic gas main installed in 1976 let natural gas travel roughly 150 feet underground into the house, where the furnace ignited it 1. The agency issued its final pipeline investigation report, PIR-26-02, on March 31, 2026 1. KSL.com reported the findings from the final report 4.

The report records one fatality, no injuries, and property damage of $1,030,443 1. Several nearby residences were damaged and families displaced 1. The South Jordan Fire Department arrived about six minutes after the first 911 call 1. Technicians from Enbridge Gas Utah, the home's gas provider, arrived about 3:45 p.m., and the board records that their bar-hole testing and pressure testing continued for more than 21 hours before the leak was located; Enbridge isolated it about 12:16 p.m. on Nov. 7 1.

The pipe The failed main was a 4-inch-diameter Aldyl A polyethylene line, manufactured and installed in 1976, running north-south in the middle of 3200 West behind the home 12. Aldyl A is a DuPont product no longer manufactured or used in new pipelines 1. The main was operating at about 45 psig, below its maximum allowable operating pressure of 60 psig 1.

The NTSB's materials laboratory traced the failure to crack growth that began on the pipe's inner wall at a single point, aligned with an oblong impression on the outer surface 1. Investigators determined a rock impingement in the backfill likely caused the impression and the crack, which extended as much as 3.5 inches along the pipe 1. The crack breached the outer wall in a single abrupt event, and flow testing measured a release of up to 48.7 standard cubic feet per minute at 43 psig, about the operating pressure at the time 1.

Post-explosion readings showed gas had spread about 250 feet from the leak, under the street, the backyard and the front yards of two homes, and technicians detected gas in the atmosphere of the adjacent house 1.

Why it went unnoticed Residents told the Utah Deputy State Fire Marshal they knew what odorized gas smells like and had smelled none. Some family members had felt dizzy and had headaches; the basement water heater stopped working on Nov. 3 and its pilot could not be relit on Nov. 5; a candle lit that evening burned with an unusually high flame 1. There were no natural gas alarms in the home 1. The report states gas may have been present inside for at least three days 1, and found that odorant had been stripped from the gas as it moved through soil — a depletion the agency has documented in earlier explosions, including in Dallas in 2018 and Silver Spring, Maryland, in 2016 1.

The agency's lessons-learned section states that gas alarms would have alerted occupants before concentrations reached an explosive level, and cites its earlier recommendation, P-25-05, that installation of natural gas alarms in homes and businesses be required 1. The water heater was shut off at the control point, leaving the furnace as the only credible ignition source; its control valve showed thermal damage consistent with that role 1.

The safeguards that did not hold Three measures the company had in place were examined in the report. Enbridge's most recent distribution leak survey of the area was conducted April 29, 2022, two years before the explosion, against a regulatory requirement of one every five years; the NTSB found the crack propagated too rapidly for the survey to catch it 1. A 2014 California Public Utilities Commission study cited in the report predicted failures for Aldyl A of this vintage under stress at some point between 22 and 235 years after installation — a range the NTSB said was too imprecise, given unknown backfill conditions, for Enbridge's evaluation to characterize the rock-impingement threat or to pick effective replacement targets 1.

Scale of the pipe in the ground Enbridge's 2023 distribution integrity management report, cited in the NTSB's factual record, counted 8,961,233 feet — about 1,697 miles — of Aldyl A mains in its Western Region, which includes Utah and Salt Lake counties 2. After the explosion the company divided its early-vintage Aldyl A into risk tiers: 548 miles rated High-High, with histories of leakage, and 1,269 miles rated High, without 2. An advanced mobile leak detection survey has been completed on the 548 High-High miles and was under way on the 1,269 High miles, with Enbridge planning in 2026 to repeat both surveys and extend coverage to medium-risk Aldyl A 2.

Utah pipeline safety inspectors had flagged the question earlier: during a 2021 inspection, state reviewers recommended that the risk of certain Aldyl A vintages be rated higher than Enbridge's own risk process had determined 2.

What the company has done, and has not Enbridge replaced about 1,000 feet of the early-vintage 4-inch main and four Aldyl A services on 3200 West 2. Its own submission to the investigation records the work as running from Nov. 14 through Nov. 20, 2024, "approximately 1,000 feet of main and 4 services" 3; the NTSB's integrity management factual report gives the completion date as Nov. 18, 2024 2. The two records differ on the end date. It also revised two standard practices for leak investigation — requiring leak screening around the perimeter of any structure and bar-hole testing at structure corners and over other gas assets in the area 13 — and updated its risk analysis for early Aldyl A by generation, based on an 11-year leak history 2. The company committed to increase capital spending on risk-informed replacement of high-risk Aldyl A 1. It has also distributed natural gas and carbon monoxide alarms with the American Red Cross in the Salt Lake City area and, with South Jordan, at an event the report expected in May 1.

What has not happened, as the factual record describes it: at the time of the explosion Enbridge had no formal Aldyl A replacement program, and the NTSB's integrity management report states that the company had not proposed one to the state utility commission 2. Targeted replacements have been carried out inside its normal capital program, with costs recovered in later rate cases, and the report notes that a broader replacement program would require collaboration with the Public Service Commission 2.

The litigation The family of the person who died filed a wrongful death suit against Enbridge Gas in Salt Lake County's 3rd District Court, seeking more than $300,000 and alleging negligence in maintaining the line and intentional infliction of emotional distress, KSL.com reported 5. In October 2025, Enbridge asked Judge Kara Pettit to dismiss the strict liability claim, arguing that transporting natural gas has not been treated as an ultra-hazardous activity; the family's attorney argued the claim exists under Utah law since the 1995 Walker Drug case 6. The judge took the motion under advisement and said she would rule in writing 6. The Ledger found no public record of that ruling in the sources reviewed for this report.

The NTSB report itself notes that federal law bars its use as evidence in a civil action for damages arising from the accident it describes 1.

What the record leaves open Whether the pipe under the rest of the city is replaced on a schedule, and at whose cost, is a question for the Public Service Commission, not the NTSB, which assigns no fault and issues no orders to operators 12. The report's alarm recommendation, P-25-05, is a recommendation to regulators, and the agency's finding in this case is that alarms, not surveys, were the safeguard that would have given the household time to leave 1.

The Ledger does not name the person who died, the school they attended or the address of the home; §4 of the paper's editorial standards withholds identifying detail about minors in any context, including adverse ones.