OKLAHOMA CITY -- It could take months for officials to determine what caused an explosion at an Oklahoma refinery that killed one worker and critically injured another, a spokeswoman with the U.S. Department of Labor said Monday.
The plant, Wynnewood Refining Co., owned by CVR Energy Inc. of Sugar Land, Texas, was shut down for scheduled maintenance and upkeep, known as a "turnaround," when a boiler that was being brought back online exploded Friday evening. The turnaround resumed Saturday at the refinery.
Billy Smith, 34, of Pauls Valley, Okla., was killed and Russell Mann of Davis, Okla., remained hospitalized in critical condition Monday at the University of Oklahoma Medical Center in Oklahoma City. His age was not released.
Investigators with the federal Occupational Safety and Health Administration arrived at the scene Saturday and were expected to remain there for up to a week, said Elizabeth Todd, a spokeswoman with the labor department.
"They will go out to the site to determine violations, if any, and the cause of the incident," Todd said. "Every case is different. It could take weeks; it could take months. Citations and possibly fines will be issued if violations are found."
Todd said she could not discuss what investigators have found while the investigation is under way.
CVR Chief Executive Officer Jack Lipinski released a statement Sunday that said the company was "cooperating fully" with the investigation.
"Our focus is to determine how this accident occurred and what steps must be taken to avoid a repeat of this incident," Lipinski said.
CVR purchased the refinery, which has a daily capacity of 70,000 barrels of crude and produces gasoline, diesel fuel, military jet fuel, solvents and asphalt. from Gary-Williams Energy Co. in 2011
Previous incidents at the refinery include a boiler explosion in 2010, a propane leak in 2008 and fire that was sparked by lightning in 2007.
There were no injuries in those incidents.