The lawsuit alleges the utility failed to mark a gas line accurately and delayed stopping the flow after a leak was reported.
DALLAS — The owners of an Oak Cliff apartment complex destroyed in a natural gas explosion have sued Atmos Energy, alleging failures in pipeline maintenance, underground-line marking and emergency response contributed to the blast that killed three people.
The lawsuit was filed in Dallas County nearly two months after the May 28 explosion leveled The Clyde Apartments at 409 E. Ninth St. The property owners accuse Atmos of negligence, gross negligence, nuisance and trespass. They are seeking compensation for the destroyed building, lost rental income, business losses, legal costs and additional damages.
The allegations have not been proven in court. Atmos Energy has said it does not comment on pending litigation and had not publicly answered the apartment owners’ latest claims. After the explosion, the company said a construction crew unrelated to Atmos damaged a natural gas line and that a professional third party had been hired to identify underground utility lines before work began.
The owners’ petition alleges Atmos received notice through the Texas 811 system two days before drilling was scheduled near the apartment complex. The lawsuit claims the utility failed to ensure that a service line beneath the planned drilling area was marked accurately. A soil-testing crew later struck the line, according to a preliminary investigation by the National Transportation Safety Board.
The NTSB’s preliminary findings are not a final determination of probable cause or legal responsibility. The federal agency is continuing to investigate the pipeline damage, the release of natural gas and the events that led to the explosion. A final report is expected to take more than a year.
The lawsuit also challenges Atmos’ response after the leak was reported. Dallas Fire-Rescue received a gas-leak call at 12:49 p.m. May 28 and notified Atmos two minutes later, according to the court filing. The explosion occurred at about 1:15 p.m. The petition says an Atmos crew arrived about five minutes after the blast and alleges the gas flow was not fully stopped until more than an hour later.
Firefighters had reached the property before the explosion and were preparing to evacuate residents. Dallas Fire-Rescue Chief Justin Ball said crews were securing the street, locating the suspected leak, putting on protective equipment and establishing a water supply when the building exploded. No firefighters were injured.
The explosion and fire killed community activist Sylvia Collins, 79, as well as Marisol Perez and her son, Erick. Five other people were injured. The two-story complex contained 23 apartments occupied by 19 families, according to fire officials. Rescue teams searched the destroyed building with drones, trained dogs and specialized equipment before officials determined that no additional residents were missing.
The property owners allege Atmos knew that parts of its polyethylene distribution system could be vulnerable to brittle cracking but failed to inspect, maintain, repair or replace portions of the system adequately. The petition describes those claims as part of a broader pattern of safety failures. Atmos has disputed key allegations made in related lawsuits and has pointed to the drilling contractor’s contact with the pipeline.
The apartment owners’ case joins lawsuits brought by survivors and relatives of those killed. One survivor’s suit alleges that gas leaks had been reported at the property during the weeks before the explosion and that the pipeline was marked in the wrong location. Atmos disputes those claims.
A Dallas County judge has ordered Atmos to preserve records, pipeline materials and other evidence connected to the explosion while the lawsuits and federal investigation continue. The preservation order does not decide fault but is intended to ensure that evidence remains available to the parties and investigators.
The competing claims leave several major questions unresolved, including who was responsible for the inaccurate line location, whether the pipeline system was maintained properly and whether the gas supply could have been stopped sooner. Those issues are expected to be examined through court discovery and the NTSB investigation.
Author note: Last updated July 29, 2026.