Explosion and fire at the Tesoro Refinery in Anacortes kills seven refinery workers on April 2, 2010.

  • By Daryl C. McClary
  • Posted 3/12/2011
  • HistoryLink.org Essay 9717
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Early Friday morning, April 2, 2010, an explosion and fire erupt in the Naphtha Hydrotreater Unit at the Tesoro Refinery in Anacortes, killing seven refinery workers in the process of returning the heat exchangers to operation after being down for maintenance. The tragedy is the worst industrial accident to date since the Department of Labor and Industries began enforcing the Washington State Industrial Safety and Health Act (WISHA), enacted in 1973.

Refining Crude Oil

The Tesoro Refinery, sitting on 900 acres at March Point near Anacortes, was constructed by Shell Oil Corporation in 1955 at a cost of $75 million. In 1997, Shell and Texaco, Inc., which operated an adjacent oil refinery, wanted to combine their refining and gasoline retailing operations in the West and Midwest. Critics maintained that the merger would violate federal and state anti-trust laws by giving the two oil giants too big a share of the market, reducing competition and leading to higher gasoline prices. As part of a consent agreement between the Washington State Attorney General’s Office and the two oil companies, Shell agreed to sell its refinery operation in Anacortes in return for allowing the merger proceed.

Equilon Enterprises was formed on January 16, 1998, by a merger of Shell and Texaco and the new company renamed the Texaco Refinery the Equilon Puget Sound Refining Company. In May 1998, Tesoro Petroleum Corporation, based in San Antonio, Texas, bought the Shell Oil Refinery for $237 million, renaming it the Tesoro Anacortes Refinery. Tesoro is the second largest employer in Anacortes, with approximately 360 full-time employees and 100 contract workers, contributing approximately $33 million in salaries and taxes to the local economy. The plant refines up to 120,000 barrels of Alaskan North Slope and Canadian crude oil per day into gasoline, turbine, and jet fuel, diesel oil, liquid petroleum gas, heavy fuel oils and asphalt, mostly for markets in Washington and Oregon.

A Huge Fireball

At 12:30 a.m. Friday, April 2, 2010, a heat exchanger in the Naphtha Hydrotreater Unit at the Tesoro Refinery ruptured, releasing hydrocarbon vapor which almost immediately exploded. Naphtha, a highly-flammable liquid produced as part of the refining process, flows through a bank of heat exchangers (metal cylinders 30 feet long) on its way for further processing. A heat exchanger raises the temperature of material entering a processing unit and cools the product going out. The explosion occurred as a team of seven refinery workers were returning the heat exchanger units to operation after being shut down for routine maintenance. A huge fireball illuminated the night sky over the refinery, followed by a violent shock wave that shook homes and rattled window in nearby Anacortes. A few minutes later, the refinery’s "wildcat whistle" sounded, signaling an emergency. For 90 minutes, fire raged in and around the fractional distilling tower where the blast occurred.

While battling the blaze, Tesoro firefighters attempted several times to search for survivors but were driven back by the intense heat. When the fire was finally extinguished and the smoke cleared, rescue workers discovered that three refinery workers had perished in the explosion and four had been severely burned. The burn victims were airlifted to the UW Burn Center at Harborview Medical Center in Seattle for treatment.

The refinery workers killed in the explosion were Daniel J. Aldridge, age 50, Anacortes; Matthew C. Bowen, age 31, Arlington; and Darrin J. Hoines, age 43, Ferndale. The four burn victims were: Matt Gumbel, age 34, Oak Harbor; Lew Charles Janz, age 41, Anacortes; Kathryn Powell, age 29, Burlington; and Donna Van Dreumel, age 36, Oak Harbor. Both Kathryn Powell and Donna Van Dreumel, burned over more than 50 percent of their bodies, died at UW Burn Center on Friday.

What Went Wrong

At 2:06 a.m. Tesoro notified the Washington State Department of Labor and Industries (L&I), Division of Occupational Safety and Health (DOSH), which enforces WISHA and investigates all workplace fatalities, of the event. DOSH immediately launched an investigation and notified the U.S. Chemical Safety Board (CSB) in Washington D.C., which dispatched a team of six investigators to the scene.

On Saturday, April 3, 2010, a team of DOSH inspectors from Olympia arrived at the Tesoro Refinery to begin the arduous task of reconstructing what led to the explosion. The onsite investigation was temporarily halted, however, while an abatement team removed asbestos from the blast area. The cleanup took four weeks to complete. Meanwhile, investigators began the lengthy process of interviewing witnesses and reviewing records to determine what went wrong and whether the safety rules were followed.

Skagit County Deputy Coroner Robert Clark determined that Aldridge, Bowen, and Hoines died from inhalation of toxic substances and extensive third-degree burns. The deaths were ruled accidental. Robert Hall, CSB supervising investigator, determined all of the workers were within 50 feet of the ignition point and had no chance of escaping before the large release of naphtha vapor exploded. He was amazed anyone had survived the initial blast, let alone the subsequent fire.

A severely burned victim usually has about a 50 percent chance of surviving the first 48 hours of trauma. After that time period, the patient’s chance of survival starts to increase gradually. Lew Janz, suffering third-degree burns over major portions of his body, was put in a medically induced coma and kept breathing with a respirator. Tragically, he died from medical complications early Tuesday morning, April 13, without regaining consciousness. Matt Gumbel, also suffering from third-degree burns, had been upgraded from critical to serious, a hopeful sign, but he died from medical complications early Saturday morning, April 24, 2010. The following day, Sunday, a community memorial for all seven refinery workers held at Anacortes High School was attended by some 800 people.

Willful Violations

In mid-May, investigators finally gained access to the Naphtha Hydrotreater Unit and confirmed that one heat exchanger in a bank of several, had ruptured, spraying naphtha vapor into the workspace. The volatile gas immediately found an ignition source, resulting in the catastrophic explosion and fire. As part of the investigation, the heat exchangers were dismantled and sent to a metallurgy laboratory in Cleveland, Ohio, to determine the cause of the failure. Tests revealed that over the years cracks had developed in many of the welds of the heat exchanger that ruptured and in at least one other unit. Tesoro had neglected to properly inspect the heat exchangers when it took over the refinery in 1998 and again during a scheduled inspection in 2008. The explosion could have been prevented either by replacing or repairing the defective units.

On Monday, October 4, 2010, after a six-month investigation, L&I issued its final report, which stated that the deadly explosion at the refinery had been entirely preventable. Tesoro Petroleum was cited for 39 willful violations and five serious violations of state workplace and safety health regulations and issued a record fine of $2.38 million, the largest in the agency’s history. (A willful violation, as defined by L&I, is where an employer knowingly violates a rule and is clearly indifferent to correcting it. A serious violation is where there is a substantial probability of serious injury or death.)

According to the L&I report of investigation, "The equipment also leaked hot, volatile and flammable vapor and liquid from flanges and other connections for years, especially when starting up following a shutdown. Tesoro’s repair efforts, including clamps, were ineffective and when they could not correct the problem, workers had to disperse the flammable vapors with long tubes called 'steam lances' in an effort to prevent ignition. Employees did this work in hard hats, gloves, goggles and basic flame-resistant coveralls, which was inadequate protection for the hazards they faced" ("L&I Issues Record Fine in deadly Tesoro Explosion"). 

Failing to Inspect, Failing to Test, Failing to Repair 

Tesoro’s long list of willful violations included: "Failing to inspect equipment consistent with recognized engineering practices and industry standards; failing to test for cracks and other defects in equipment prone to damage from thermal fatigue, chemical exposure; failing to implement its own corrosion awareness and management program" ("L&I Issues Record Fine in deadly Tesoro Explosion"). The company also failed to repair equipment, had no start-up protocols for the heat exchangers, describing the potential hazards, and neglected to ensure workers were properly trained for the task.

"The loss of seven lives is a tragedy, not just for the loved ones, but for our entire state. What makes the loss of these lives all the more painful is that these deaths could have been prevented," said Governor Christine Gregoire (b. 1947). "I believe the actions of L&I is announcing today and the record fine they have assessed against Tesoro sends a clear message that these tragedies are not acceptable" ("L&I Issues Record Fine in deadly Tesoro Explosion").

Sources: Bill Virgin, "Texaco, Shell to Merge Operations in the West," Seattle Post-Intelligencer, March 19, 1997, p. A-4; "Larry Lang, "Shell Forced to Sell Anacortes Refinery," Ibid., December 20, 1997, p. B-1; Bill Virgin, "Tesoro To Buy Shell Refinery in Anacortes," Ibid., May 5, 1998, p. C-1; Ross Cunningham, "Customs Collector Starts Oil Flow at Anacortes Refinery," The Seattle Times, August 25, 1955, p. 23; Jack Broom and Sara Jean Green, "Five Dead in Anacortes Refinery Explosion and Fire," Ibid., April 3, 2010, p. A-1; Jim Brunner, Craig Welch and Steve Miletich, "Refineries Have History of Safety Violations," Ibid., April 3, 2010, p. A-1; Craig Welch, "Refinery Tragedies All Too Common," Ibid., April 4, 2010, p. A-1; Lynda Mapes, "Long, Painful Recovery Awaits Blast Survivors," Ibid., April 4, 2010, p. A-8; Mike Carter, "Tesoro Blast Called Fireball," Ibid., April 6, 2010, p. B-1; "New Scrutiny, Old Fears," Ibid., April 6, 2010, p. A-13; "Around the Northwest: Anacortes; Work Cut at Tesoro Refinery," Ibid., April 13, 2010, p. B-2; "Sixth Victim of Blast at Refinery Has Died," Ibid., April 14, 2010, p. B-8; Lynda V. Mapes, "Seventh Anacortes Refinery Victims Dies," Ibid., April 25, 2010, p. B-1; Janet I. Tu, "Refinery Victims ‘Are Us and We Are Them,’"  Ibid., April 26, 2010, p. B-1; George Tibbits, "Tesoro Extends Closure of Refinery," Ibid., June 11, 2010, p. B-4; Susan Gilmore and Craig Welch, "State: Tesoro Blast Preventable," Ibid., October 4, 2010, p. A-1; "L&I Inspectors to Investigate Fatal Explosion at Tesoro Refinery," April 2, 2010; "Interviews, Meetings as Tesoro Refinery Investigation Begins," April 9, 2010; "Asbestos Limits Access to Refinery," April 13, 2010; "Seventh Tesoro Worker Dies," April 26, 2010; "L&I Issues Record Fine in deadly Tesoro Explosion," October 4, 2010, Washington State Department of Labor and Industries website accessed October 8, 2010 (www.lni.wa.gov).

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