BP Supervisor Joseph Garcia was killed when a bolted-down metal lid flew off a water filtration vessel as it was being restarted, CSB said. The filtration system is attached to a compressor on the refinery's ultracracker unit, which makes raw materials used to process gasoline and other products.
According to CSB Lead Investigator Don Holmstrom, because the bolts were “either sheared off or stripped” as well as “propelled a large distance away,” only a very significant force could have the metal lid blown off in such a manner.
A variety of scenarios could explain the sudden build-up of pressure inside the filtration vessel, Holmstrom said. According to CSB, an explosion may have occurred inside the filter. Holmstrom stated that several witnesses told CSB that the process water used in the filtration system “sometimes contained hydrogen, flammable light hydrocarbons and hydrogen sulfide, a toxic and flammable gas.” He explained that when in the presence of oxygen and an ignition source, these substances could become fuel for an explosion.
“Typically in refinery service, when flammables may be present, it is critically important to remove oxygen to avoid possible fires and explosions,” Holmstrom noted. “We are examining BP’s procedures and practices to understand if air may have in fact remained in the filtration system.”
Investigation Could Take Months
Although the agency team interviewed approximately 35 witnesses, including several who were in the accident’s immediate area, CSB Board Member William Wark said the probe could take a number of months.
“The goal of this investigation is to determine as precisely as possible what happened to cause this unfortunate event and to make recommendations to BP and to others to prevent similar accidents in the future,” Wark said.
According to Wark, CSB weighed a number of factors when deciding to proceed with the investigation, including the “severity of the accident, the likelihood of the hazardous chemicals were involved and the learning potential for BP and other refiners that operate similar processes.”
Wark added that CSB also considered the string of accidents that occurred at the Texas City refinery in the past 32 years. A total of 41 people died since then in workplace accidents at the site, according to CSB.