WASHINGTON (March 1, 2018) — The National Transportation Safety Board’s investigation of the Feb. 23, 2018, natural-gas related house explosion in Dallas continues Thursday while local emergency management agencies and ATMOS Energy address the immediate life-safety needs of the affected community.
A natural-gas fueled explosion at about 6:45 a.m., (CST) Feb. 23, destroyed the single-family home at 3534 Espanola Drive, Dallas, killed a 12-year-old girl and injured several others.
The NTSB decided to investigate the accident and a team of three investigators arrived on-scene the morning of Feb. 25. During the initial assessment of the accident site, investigators learned of two other homes in the immediate vicinity that were damaged by two separate explosions/fires two days earlier.
(In this image provided by ATMOS Energy, the locations of the Feb. 23, natural-gas related explosion
(lot marked in yellow) and two homes destroyed by fire Feb. 21 and 22, (lots marked in green) are depicted.)
The NTSB’s investigation is focused on the explosion at 3534 Espanola Drive. The investigation is an objective, independent and comprehensive examination of all the factors and circumstances surrounding the accident. Investigators will gather evidence and conduct analysis of the data they gather to determine the probable cause of the explosion, learning all they can from the tragic accident to prevent similar accidents.
Part of the NTSB’s comprehensive investigation is looking at the gas company’s integrity management and operations procedures and their response to the accident, as well as the actions of state and local emergency response agencies. The Railroad Commission of Texas and the Pipeline and Hazardous Materials Safety Administration are parties to the investigation and are providing techinical assistance and support to the NTSB investigator in charge.
NTSB investigators have thus far interviewed 11 Dallas Fire and Rescue department personnel and four ATMOS Energy employees who responded to the Feb. 21 and 22 house fires.
Unfortunately, continued rain has hampered evidence collection and excavation of pipelines near Espanola Drive. ATMOS Energy employees, along with NTSB investigators, have been working to identify the location of leaks on the gas distribution main line and collect physical evidence in the area.
A leak has been found at a service tee connection to 3524 Espanola Drive. This 6-foot long distribution mainline segment has been collected and will be shipped to the NTSB materials laboratory in Washington for examination. The NTSB plans to conduct further pressure tests on customer gas lines at 3534 Espanola Drive in the next three to four days.
(In this NTSB photo, the failed service tee connection to 3524 Espanola Drive, is tagged with
NTSB evidence tags in preparation for transport to the NTSB’s materials lab in Washington)
(In this NTSB photo, the failed service tee connection to 3524 Espanola Drive, is tagged with NTSB evidence
tags in preparation for transport to the NTSB’s materials lab in Washington)
Geologic conditions surrounding the natural gas pipelines in the vicinity of 3534 Espanola Drive is one of the many potential causes of the events on Espanola Drive and Durango Drive that the NTSB will examine in the course of its investigation.
The NTSB is in the early stages of its investigation and investigators typically remain on scene for about 10 days or as long as on-scene evidence collection requires. The NTSB will release a preliminary report shortly after on-scene evidence collection is completed. Preliminary reports do not contain analysis and do not state probable cause, rather, a preliminary report details the significant facts investigators have gathered and verified at that stage of the investigation. NTSB major investigations take between 12 to 24 months to complete.
The Pipeline and Hazardous Materials Division of the NTSB’s Office of Railroad, Pipeline and Hazardous Materials Investigations, investigates accidents occurring during the transport of natural gas and other hazardous gases, and hazardous liquids, such as gasoline, through pipeline systems. It also investigates accidents in which public safety is threatened by the release of hazardous substances during transportation. Pipeline accidents in which there is a fatality, substantial property damage, or significant environmental impact may be investigated by the division.
The NTSB is an independent federal agency that has no regulatory or oversight authorities. Inquiries regarding safety oversight of ATMOS Energy operations in Dallas should be directed to the Railroad Commission of Texas. Inquiries regarding ATMOS Energy’s response to the explosion should be directed to ATMOS Energy.
The NTSB’s authority to investigate pipeline accidents stems from Title 49, Code of Federal Regulations, Section 831.40(a)(2) and 831.40(b). While the NTSB arrives at the scene of a transportation accident as quickly as possible, in order to preserve perishable evidence, the NTSB is not a first responder agency and is not involved in the immediate life-safety issues of incident response. Rather, the NTSB’s mission is charged by Congress with investigating every civil aviation accident in the United States and significant accidents in other modes of transportation. The NTSB determines probable cause of those accidents and issues safety recommendations aimed at preventing future accidents.
Should the NTSB discover, through the course of its investigation, a safety issue that represents an imminent threat to safety, the board can issue urgent safety recommendations before an investigation is completed.