Cause of death released for 11 victims in Washington chemical tank rupture

 The 11 people killed after a chemical tank ruptured at a pulp and paper mill in Washington state last month all suffered chemical burns, officials said Thursday while releasing the autopsy results.

The incident occurred May 26 at Nippon Dynawave Packaging in Longview, located about 50 miles northwest of Portland, on the Washington-Oregon border.

A tank containing white liquor, a chemical mixture used in the paper-making process, catastrophically failed in what authorities have described as a blast that damaged much of the facility.

White liquor, which is used to break down wood into paper pulp, is made up of sodium hydroxide, sodium sulfide and disodium carbonate, authorities said. The 900,000-gallon tank was approximately two-thirds full at the time of failure. 

Eleven employees died and multiple others were seriously injured in the incident, officials said.

The Cowlitz County Coroner's Office conducted the autopsies for 10 of the victims. 

Eight of them died from alkaline chemical burns, the office said: Jared Ammons, 35; Norman Barlow, 58; Gilberto Bernal, 52; Bradley Covington, 27; Tyler Covington, 29; Clinton Doran, 26; John Forsberg, 51; and Dale Miller, 54.

Robert Wilson, 48, died from alkaline chemical burns and blunt force injuries, and Braydon Finkas, 38, died from alkaline chemical burns and "asphyxia due to aspiration of foreign object," the coroner's office said. 

One of the victims, 27-year-old Dillon Miller, was transported to a hospital in Portland, where he died from his injuries. The Multnomah County Medical Examiner said his cause of death has been determined to be due to sodium hydroxide and sodium sulfide burns, which it noted is consistent with the other causes of death from alkaline chemical burns.Cowlitz County Coroner Dana Tucker said the "horrific tragedy" is one of the most significant the community has seen since the eruption of Mount St. Helens in 1980.

State and federal agencies are investigating to determine how the incident occurred and what can be done to prevent something similar from happening in the future.

The Washington State Department of Labor and Industries said its probe will also look to identify any workplace safety violations and is expected to take around six months