William M. Welch

USA TODAY

10 are hospitalized

Cause of the blast not yet determined

Officials say all others in plant accounted for

Two people were killed when an explosion ripped through an Omaha animal feed processing plant Monday collapsing part of the building, officials said.

Omaha Police Lt. Darci Tierney said others working in the plant at the time of the blast have been accounted for.

Douglas County Attorney Don Kleine, who oversees the coroner, confirmed two deaths at the plant.

Interim Fire Chief Bernard Kanger had earlier said an unknown number of workers could still be inside the International Nutrition plant in south-central Omaha.

Kanger said the plant is unstable, and rescue and recovery workers had to move slowly and carefully inside the structure.

He said 10 people were hospitalized, including four in critical condition, and another seven declined medical attention for injuries.

He said 38 people were working in the plant at the time of the blast.

The cause of the blast has not yet been determined. Kanger said there were no hazardous chemicals at the plant.

A forklift operator, Kendrick Houston, told the Omaha World-Herald he was walking on the plant's main floor after a morning break when it began to tremble.

"There was this real loud crackling sound, and the lights went off," Houston told the newspaper. "I saw a spark, and there was a big ball of flame coming from the southwest corner of the building."

He and a co-worker hit the ground as debris, smoke and dust rained on them.

"It happened so quick," said Houston, 38. "Then we just got up and ran out."

Once outside, Houston decided to try to go back into the plant to help coworkers still inside.

"I ran back in," Houston said. "I yelled their names, but they didn't answer."

"It was disarray," Houston said. "All the lights were out. It was pitch black. ... I think it was still burning in that corner."

Plant worker Nate Lewis, 21, said he was on the first floor when he heard the blast. The building went dark, so he used light from his cellphone to make his way across the production floor to safety outside.

"I was a production line worker, although I don't know if I want to be that anymore," said Lewis, who's worked at International Nutrition for about four months.

The plant sits in an industrial area visible from Interstate 80, which bisects Nebraska's largest city. There are no residences nearby and no other buildings were evacuated after the explosion.

Jamar White said he heard a loud crack and then looked up to see the back wall of the building collapsing.

"I ran at least 150 feet," White said. "I ran far enough to make sure nothing else would keep falling."

Afterward, White said, he could see inside the third floor of the building where at least two co-workers were screaming for help.

Contributing: Associated Press