Crews have recovered the remains of one more victim of a massive chemical tank rupture at a paper mill in Washington state, authorities said Friday, leaving two workers still unaccounted for. Among the 11 workers killed in the disaster were two brothers who worked there together, a trivia champ and an electrician who would help his farmer neighbors cut hay.A tank containing more than 500,000 gallons (1.9 million liters) of a mixture used to break down wood for making paper collapsed Tuesday morning at the Nippon Dynawave Packaging Co. in Longview, a city of 40,000 along the Columbia River.The collapse expelled a flood of caustic chemicals powerful enough to blow out building walls and overturn pickup trucks at the site. The liquid, called white liquor, causes severe burns on contact and lung damage if vapors are inhaled.

What happens during the recovery processThe recovery of victims has been slow and methodical, complicated by the dangers posed by the remaining chemicals and other industrial hazards, said Matt Amos, Longview fire battalion chief. Six bodies were found on Thursday. That night, crews used vacuum trucks to siphon away much of the remaining liquid, allowing search teams to look farther into the site on Friday, Amos said.Crews were steering clear of a zone closest to the tank and they’ve been working with engineers to determine which damaged buildings near it are safe to enter.