Jan. 21, 2014 -- Recovery efforts continued Tuesday after a manufacturing plant explosion in Omaha, Neb., that killed two workers and hospitalized 10 others with serious injuries.
This morning, the International Nutrition plant is a twisted, dangerously unstable wreck. Key structural supports failed after the blast, and the second and third floors of the plant collapsed on top of the first floor. The blast knocked out the lights in the building and sent workers fleeing for safety.
Investigators still aren't sure exactly what happened – and now they're trying to solve the deadly mystery.
Omaha Interim Fire Chief Bernie Kanger said the investigation could take weeks. He also noted there were no hazardous chemicals at the plant, which makes products that are added to livestock and poultry feed to make them more nutritious.
"We've got tens of thousands of pounds of concrete, reinforced concrete and steel," Kanger said. "This is a very significant rescue operation."
Fifty firefighters were called to the collapsed building, working to free the trapped workers. Thirty-eight people were in the plant when the explosion occurred.
One of those workers, John Broderick, sent his fiancée, Kari Cook, a text message when the building collapsed, according to WOWT 6 News.
"Major accident. I'm hurt and trapped. Love you," the message reads.
Broderick was rescued along with nine others, but many of those workers sustained serious injuries. At least two people have died, but officials haven't cleared the entire structure yet.
Records show that the plant owner, International Nutrition, was hit with half a dozen "serious" violations in 2012 – including problems with wiring and safety equipment. The company has declined to comment on those violations or the accident.
The Associated Press contributed to this report.