Tyson Foods Inc. entered a guilty plea and agreed to pay a $500,000 fine for violations that resulted in the death of a worker at a plant in Texarkana, as reported by the Associated Press. The world''s largest meat company, pleaded guilty in U.S. District Court to a "willful violation of an OSHA standard resulting in the death of an employee," prosecutors said. The violation is the most serious offense under Occupational Safety and Health Administration regulations, according to the Justice Department. An accident at a facility that converts poultry products into animal feed killed worker Jason Kelley on Oct. 10, 2003. In addition to the $500,000 fine, the company was fined a separate $436,000 by OSHA in 2004 over the same incident. Tyson spokesman Gary Mickelson says the company is in talks about a possible settlement of the OSHA levy. Kelley was killed when he was exposed to hydrogen sulfide gas while repairing a leaky piece of equipment. Another plant worker and two emergency responders were hospitalized after they tried to help Kelley, and another two workers were treated at the scene. Mickelson provided a statement in which the company expressed regret. The death occurred at the River Valley Animal Foods plant, where Tyson recycles protein and fats for livestock feed and inclusion in pet food. The Justice Department says the rendering process includes high-pressure steam processors, called hydrolyzers that are used to create feather meal from poultry feathers. A product of the feather decomposition is hydrogen sulfide gas, which is toxic. The government said the hydrolyzers needed frequent maintenance and that workers were exposed to hydrogen sulfide gas as they worked. A statement from prosecutors said Tyson safety personnel and management were aware at the time that the gas was present at the facility and that Tyson did not take enough steps to reduce exposure within prescribed limits. The company also failed to have controls or protective equipment and did not provide effective training, the government said. Prosecutors said an identical exposure injured a worker at the facility in March 2002. The River Valley Animal Foods plant employs about 100 people, Mickelson said.