(Longview, WA) -- Crews on the scene of a deadly chemical tank implosion at a paper mill in Longview are transitioning from a rescue mission to recovery efforts. Cowlitz County Fire Chief Scott Goldenstein announced the transition yesterday, saying no further survivors are expected to be found. Two people have been confirmed dead, while nine missing people are presumed dead. Another seven people remain hospitalized for injuries. The tank at Nippon Dynawave contained 900-thousand gallons of a noxious chemical mixture used in making paper when it imploded Tuesday. Around 600-thousand gallons of the corrosive chemical were released in the blast that overturned nearby vehicles and flooded the area. Officials say some of the chemicals have reached the Columbia River.