CHARLESTON, W.Va. -- DuPont Co. officials said Thursday that a corroded, aging hose leaked phosgene gas in a January incident that killed a worker at the company's chemical plant in Belle.Plant manager Bill Menke issued a short news release that said DuPont had provided state and federal regulators with copies of a report on the company's investigation of the Jan. 23 death of Danny Fish and a series of other plant leaks.However, DuPont did not release its report to the public, and Menke declined a request for an interview about the findings."We are not releasing the full report since there are ongoing investigations by the various agencies, and we do not want to compromise their investigations," Menke said in an e-mail message.Government agencies that received the company report said DuPont had labeled the document as confidential business information that could not be made public without a more detailed review.DuPont issued its news statement about a month before the six-month anniversary of the deadly phosgene leak. That anniversary -- on July 23 -- is the deadline for the U.S. Occupational Safety and Health Administration to issue any citations to the company. OSHA officials said they so far have taken no action against DuPont.Various agencies have focused on the Belle facility since January, after a series of incidents that included a leak of toxic and flammable methyl chloride that went undetected by plant officials for nearly a week.In the worst of the incidents, Fish, a 32-year plant veteran, was sprayed with phosgene, a chemical building block that was used as a poison-gas weapon during World War I. Fish died the following day.U.S. Environmental Protection Agency inspectors cited DuPont in March, saying the hose involved in the phosgene leak was five months overdue to be replaced. The EPA also said the flexible, braided-steel hose was the wrong kind of equipment to be used in the first place because of the extremely hazardous nature of phosgene.Inspectors from the EPA, the U.S. Chemical Safety Board and other agencies have focused on the "braided steel hose" used to transfer phosgene from 1-ton cylinders to a pesticide production unit. DuPont had said Fish was exposed to a "small residual" amount of phosgene from the hose and was taken to the hospital "as part of standard protocol for exposure to this material."In its news statement, DuPont said its investigation concluded that "several factors combined to cause the hose to fail, including the length of time the hose was in service, physical corrosion concealed by the manufacturer's label, and pressure buildup in the line."Reach Ken Ward Jr. at firstname.lastname@example.org or 304-348-1702.