The company claims that the workers had been warned of the gas and instructed not to open the tank. A co-worker disagrees:
There was no warning and no reason to suspect the presence of deadly nitrogen gas in a tank where two men died this month, a former supervising contractor at Valero has told federal investigators.The US Chemical Safety and Hazard Investigation Board is investigating the incident. Board investigator Steve Wallace noted that there had been at least one similar close call in the recent past.
Missouri resident William Pyatt is disputing company accounts of the work environment on the night John Lattanzi and John Ferguson died at the refinery near Delaware City.
In a telephone interview with The News Journal, Pyatt said he was unaware of any nitrogen risk at the work area and questioned a company claim that the two men had received verbal instructions barring them from opening the tank where their bodies were later found.
"Those guys know the status when they're told the status. It's written on the permit," said Pyatt, a contractor who was supervising several activities at the refinery on Nov. 5, the night Lattanzi, of New Jersey, and Ferguson, of Springfield, Md., died in a reactor tank.
"There was no barricade. There was free access, and that's definitely not typical in that situation," said Pyatt, who said he was too shaken by the accident to remain on the job in Delaware.
A copy of the permit signed by both men described their task simply as "Install Top Elbow" pipe, and listed nitrogen gas risks as N/A, or not applicable.
Stephen Wallace, lead investigator for the board's investigation in Delaware, said he was seeking additional details about an incident in November 2004 involving a carpenter assigned to scaffolding work near the plastic-covered opening of a tank filled with nitrogen gas.The Board has published a bulletin warning of the hazards of nitrogen asphyxiation stemming from a 1998 incident at a Union Carbide plant that killed one worker and seriously injured another.
Another worker who was supplying the nitrogen gas from a truck spotted the carpenter and sounded an alarm that brought the employee out of danger.
"We're looking at all the near-miss reports. We're currently in the process of gathering information. That's about all I can say at this point," Wallace said.
These deaths ocurred at the same plant, then owned by Motiva, where a worker was killed when a tank of sulphuric acid exploded. That incident was also investigated by the Chemical Safety Board.