Investigators are looking into the cause of a crane-boom failure that killed a worker at the construction site of Motiva’s Port Arthur refinery on April 19.

The worker killed has been identified as Stewart Wayne Shaver, 41, who was working for Beacon Construction, a subsidiary of Bechtel Corp. Francis Canavan, a spokesman for Bechtel, wouldn’t comment on the circumstances surrounding the incident, saying it was still under investigation. However, he did say the crane used was a Bechtel-owned Link-belt RTC-8090 Series II, a 90-ton rough-terrain crane.

The refinery is undergoing a 325,000-barrel-per-day expansion by a joint venture of San Francisco-based Bechtel Corp. and Pasadena, Calif.-based Jacobs. When complete, the refinery will produce 600,000 bpd, making it the largest refinery in the U.S. and one of the top 10 in the world. The construction phase of the expansion began in fall 2007. Completion is scheduled for 2012.

Federal investigators from the Occupational Safety and Health Administration and local law enforcement officials are investigating the accident. Calls to OSHA and the Jefferson County, Texas, Sheriff’s Dept. were not returned. The United Steelworkers (USW) union headquarters in Pittsburgh, says four to five minor incidents involving cranes have been reported at the site.

The death has been overshadowed by the April 20 explosion on the Deepwater Horizon oil rig off the coast of Louisiana, an accident in which 17 workers were injured and 11 went missing. But the USW says both incidents are related and point to an overarching problem with process safety in the oil-and-gas industry.

“This is the oil industry’s fourth health-and-safety incident involving worker deaths or injuries in the past two and a half weeks,” says USW International Vice President Gary Beevers. “How many more workers have to pay the price for the industry’s lack of a safety culture? The industry is long overdue for a complete overhaul of its health-and-safety provisions.”

In addition to the Port Arthur accident and the Deepwater explosion, six workers were killed as a result of an April 2 explosion and fire at Tesoro’s Anacortes, Wash., refinery. On April 14, three workers were injured, two seriously, in a fire at ExxonMobil’s Baton Rouge, La., refinery.

But Ron Chittim, a senior policy adviser for the American Petroleum Institute, Washington D.C., the industry trade group, says the industry takes all accidents and injuries seriously and works diligently to improve safety.

Refinery work is “not without risk, but the risk can be managed,” Chittim says. He said any time an accident occurs, the industry learns lessons and applies them to its safety procedures.