It was solely the negligence of Watson Grinding and Manufacturing that led to a fatal explosion at the company’s West Houston facility in January 2020, a Harris County jury determined Thursday after less than five hours of deliberation.
Jurors unanimously cleared 3M, the only defendant that did not settle prior to trial, and three other potentially responsible parties in the trial that stretched over three weeks before Harris County District Judge Denise Brown. The plaintiffs in the case — a group of six business owners whose companies were either destroyed or disrupted by the explosion — alleged 3M’s failure to properly service a gas detection system caused the disaster.
Lawyers for the plaintiffs had requested the jury find 3M at least 75 percent liable and award about $2.4 million in damages. The total awarded Thursday was about $1.9 million.
Robert Kwok of Kwok Daniel, who represented the plaintiffs, issued a statement after the verdict thanking the jury for its service and vowing that the “pursuit of justice for the families and homeowners devastated by this catastrophic explosion is far from over.”
“This trial involved business-loss claims, and we told the jury from the beginning that the damages here were modest compared to the broader human impact of this disaster,” he said. “Future trials will include dozens of community members whose homes, lives and families were directly affected by the explosion. We remain fully committed to the West Houston community that was destroyed through no fault of their own, and we are already preparing for the upcoming July and October preferential trial settings against 3M.”
Counsel for 3M was not immediately available to comment following the verdict Thursday afternoon.
Experts concluded the cause of the 2020 explosion that killed two employees and one nearby resident was an undetected propylene gas leak. About 600 gallons of the gas filled the Watson Grinding facility overnight and into the early morning hours of Jan. 24, 2020. The gas ignited at 4:24 a.m., when an employee entered the building and flipped on a light switch.
The massive explosion could be felt and heard for miles.
The company, which employed about 130 people by 2020, specialized in applying thermal spray coatings to metal parts used in corrosive environments, such as fracking, offshore oil and gas operations, refining, power generation and aerospace. Propylene gas was used in the application process.
Watson Grinding filed for Chapter 11 bankruptcy Feb. 6, 2020, and was later liquidated.
The Trial
Lawyers for the plaintiff argued the explosion was the result of 3M’s failure to properly service Watson Grinding’s gas detection system and its failure to properly communicate that an “open loop fault” between the system and the industrial computer used at the facility, called a PLC, needed to be remedied before the system could properly function.
Lawyers for the defense argued 3M technicians pointed out the issue during routine servicing multiple times and that it was the fault of management at Watson Grinding and the “culture of carelessness” permeating operations there that led to the explosion.
During opening statements, jurors learned that the January 2020 explosion wasn’t the first serious incident at the Watson Grinding facility.
In October 2008 there was a propylene gas leak that caused a fire and explosion that injured two workers. That blast also damaged the building, and a new one was constructed in 2009, according to a detailed 56-page report released by the U.S. Chemical Safety and Hazardous Investigations Board exploring the root causes of the 2020 explosion.
The defense argued throughout trial that Watson Grinding routinely failed to follow its own safety checklist implemented after the 2008 explosion.
During opening statements April 14, jurors were told by lawyers for 3M that they had subpoenaed John Watson, who was CEO of Watson Grinding until it ceased operations, and Bob White, the company’s former chief operating officer, to testify at trial, and explained that both men in their depositions asserted their Fifth Amendment right in response to questioning about the blast.
As the trial neared its end, a surprise came during testimony Wednesday morning when Watson decided instead to offer substantive responses to some questions under direct examination by Zandra Foley of Thompson, Coe, Cousins & Irons, who represents 3M.
He said his appearance Wednesday marked the “first time I’ve been in court” since the explosion. He also admitted to knowing that the light switch in the building where the thermal coatings were applied wasn’t explosion proof, but he said that was “because there are no gases” in that part of the building, as gases only flowed into the coating booths that lined the large, open room.
Foley then showed Watson and the jury an internal Watson Grinding document dated Nov. 17, 2008, that said explosion-proof measures were to be taken with all electric systems.
He also pushed back on Foley’s questions about the company’s use of a rubber hose, not graded for use with propylene gas, to move gas from an outside tank into the coating booths. She said that the rubber hose was a replacement for a metal pipe that had previously been used.
“I’ve heard different arguments about that,” he said in response to the suggestion that the wrong hose was used. “There’s no such thing as a propylene hose.”
Foley asked Watson whether the explosion would have happened had employees turned off the gas at the end of the workday as the safety checklist required. He said he agreed it would not have happened.
Under cross-examination, a lawyer for the plaintiffs, Will Hoke of Kwok Daniel, reminded jurors via questioning that Watson was testifying pursuant to a subpoena.
“They actually pulled you away from a funeral,” he began his second question before drawing a quick objection from Foley that led to a bench conference.
Hoke then asked Watson if 3M had offered equipment that would have set off strobe lights and alarm bells in the event of a gas leak, whether he would have approved the purchase.
“Yes, I thought we had that in place already,” he said.
Bob White, the former chief operating officer of Watson Grinding, also testified Wednesday morning, but he asserted his Fifth Amendment right in response to every question.
Closing Arguments
During closing arguments Wednesday afternoon, Kwok told jurors Watson Grinding was not an expert in gas detection systems, but in spray coating.
“Safety systems exist because humans make mistakes,” he said, echoing a theme he presented in opening statements. “You don’t have gas detection systems for perfect days.”
“3M was the last line of defense to protect the community,” he said, adding that 3M should have shut Watson Grinding’s operations down if it found there were issues with the gas detection system.
Kwok asked the jury to find 3M 75 percent responsible for the explosion and to apportion 25 percent of the blame to Watson Grinding.
“When you take responsibility for a life-saving system, you don’t get to walk away when that system fails,” he said.
Attorney Steve Schleicher of Maslon gave closing arguments for 3M.
“This case was supposed to be about gas detection, but what you’ve heard over the last three weeks was gaslighting,” he began, arguing that Watson Grinding had known about the dangerous issues plaguing its business for years and didn’t make any changes to fix the problems.
“Their negligence failed the community,” he said, referring to the 2,000-gallon gas tank behind the coatings building as “a bomb” in “their backyard.”
While the plaintiffs’ lawyers in court do not represent Watson Grinding, Schleicher said he could understand if the jury was confused by that because they “have been defending these folks over and over again” while “falsely accusing” 3M of causing the fatal explosion.
Schleicher again reminding jurors of the evidence they saw whether top management at Watson Grinding was informed multiple times of the problem with the gas detection sensors not being properly connected to the PLC system and never acted to fix it.
“The mouth can’t speak if the brain won’t listen,” he said, explaining the gas detection system to jurors in an analogy where the brain is the PLC, and the mouth is the alarm.
A PowerPoint presentation ran jurors through what Schleicher characterized as the numerous mistakes Watson Grinding made that led to the explosion: using the wrong hose to bring gas into the coating booths, not closing the main valve on the gas tank outside, not closing the valve that allowed gas to flow into the coating booths inside the coatings buildings, not pressing the e-stop button once a leak was suspected by employees onsite minutes before the explosion and not changing the light switch in the building to an explosion-proof version after the earlier incident.
“The very first switch they have when you enter the building is the same one you and I have in our living room,” he said.
The MDL
The lawsuits filed on behalf of more than 2,600 plaintiffs in the wake of the explosion were consolidated into multidistrict litigation for pretrial proceedings.
The first set of cases from the MDL set for trial were brought by the families of the three individuals who died in the explosion, but they settled before trial. The second group to go to trial was made up of five plaintiffs seriously injured in the explosion.
That trial ended in June 2025 with a $37.9 million verdict against 3M and Teledyne-Detcon. 3M is the former parent company of Detcon, and Teledyne purchased Detcon from 3M.
The second trial ended in November 2025, when a Harris County jury returned a $118 million verdict against 3M for seven other plaintiffs who were impacted by the explosion.
Thursday’s trial marked the third bellwether case.
About two weeks ago, 3M and Teledyne-Detcon each filed opening briefs appealing the $37.9 million verdict with the First Court of Appeals in Houston. Both companies argue the plaintiffs’ theory of liability adopted by the jury would create a new duty for inspectors and technicians that would have impact far beyond these MDL cases.
“What plaintiffs really want is for this Court to create a new duty under which inspectors and technicians, despite being hired to perform a limited scope of work, owe a broad, undefined legal duty to correct customers’ other problems and thereby safeguard unknown third persons,” Teledyne-Detcon’s brief argues.
3M, in its brief, told the appellate court that Watson’s bankruptcy effectively has “skew[ed] the litigation into a quest for entities to blame” but that the law is clear “that a person cannot be held liable for harms he has no duty to prevent, or for which he cannot be said, in any reasonable way, to cause.”
“The Court should reverse and render judgment for lack of evidence of any duty or causation,” 3M argues in the brief. “Those twin holdings will dispose of the entire litigation and put an end to the stream of trials and appeals that all turn on these two issues.”
The plaintiffs in this lawsuit are Montenegro Enterprises, doing business as New Things Furniture, LaSalvadorena Sports Bar and its owner Jose Romero, TXP Investments, Texas Plumbing, Casco Industrial Builders, Sam Hoss Enterprises, Tim Tran and Mark Marthieo.
Montenegro Enterprises, TXP Investments, Texas Express Plumbing and LaSalvadorena Sports Bar are represented by Rob Kwok, Ryan Loya, William W. Hoke, Ranny S. Sawaf and Marcos H. Cardenas of Kwok Daniel and William R. Moye of Moye Law Firm. Casco Industrial Builders is represented by Adam Lewis of Arnold & Itkin. Mark Marthieo and Sam Hoss Enterprises are represented by Ryan Pigg of the Buzbee Law Firm.
3M is also represented by Zandra Foley, Thomas Benedict, Kevin Risley and Zachary Nye of Thompson, Coe, Cousins & Irons and Connie Pfeiffer and Reagan Simpson of Yetter Coleman.
The case number for the trial that ended Thursday is 2020-40596. The case number for the appeal of the first trial is 01-25-00859-CV.