HOUSTON — We’re learning more about what led to a deadly 2020 explosion at Watson Grinding in northwest Houston. Three people, including two workers and one person at a nearby home, were killed in the blast.
Hundreds of homes were also damaged.
On Thursday, the U.S. Chemical Safety and Hazard Investigation Board (CSB) released its final report on the explosion, which pointed to what investigators say is a lack of a comprehensive safety management program and an ineffective plan for emergency response.
“As highlighted in our safety issues, Watson Grinding did not effectively train its workers on the hazards of propylene, and on the morning of the incident these workers were not warned to evacuate, instructed to prevent others from entering the area, or informed to contact emergency responders when the propylene release was suspected,” CSB investigator Benjamin Schrader said.
The explosion happened just after 4:30 a.m. on January 23 at the facility at 4525 Gessner. According to the report, there was an accidental release of propylene, a flammable hydrocarbon vapor, due to a hose that had disconnected from his fitting. The propylene built up and when an employee entered the building and turned on the light, it ignited, which led to the explosion.
The CSB found that release of propylene was the result of a “degraded and poorly crimped rubber welding hose” which came off its fitting. Investigators also found that a manual shutoff valve at the propylene storage tank wasn’t closed at the end of the previous workday and that a gas detection alarm, exhaust fan startup and gas shutoff system all weren’t working properly.
Several homes were within a few hundred feet of Watson Grinding. In all, the report says 450 structures were damaged. In December of 2020, the Houston City Council tightened regulations on businesses storing hazardous materials within the city limits.
Watson Grinding filed for bankruptcy in the weeks after the explosion.
You can read the full report here.