(Updates with news conference, adds byline)
By Katie Schubert
OMAHA, Neb., Jan 20 (Reuters) - An explosion and fire flattened part of an animal feed plant in Omaha, Nebraska, on Monday, killing at least two people and injuring at least 10 others, authorities said.
About 38 employees were working at the International Nutrition plant at midmorning when there was an explosion and part of the building collapsed, interim Fire Chief Bernard Kanger told a news conference.
At least two people were killed, and one of the bodies has been recovered, Kanger said. The other is expected to be recovered on Tuesday.
All employees have been accounted for, but authorities are not sure if there were any visitors in the plant, he said.
At least 10 people were taken to hospitals in Omaha and Lincoln. Four were in critical condition, Kanger said.
He described the explosion and fire as an industrial accident, and said an investigation would take weeks.
Forklift operator Kendrick Houston told the Omaha World-Herald newspaper he was returning to work from a break when the floor began to tremble.
"There was this real loud crackling sound and the lights went off," Houston was quoted as saying on the paper's website. "I saw a spark and there was a big ball of flame coming from the southwest corner of the building."
Houston said he fled the building. He then tried to go back in to find his co-workers, but heat and smoke forced him to turn back, he added.
Nate Lewis, a production line worker, told the newspaper that the building caved in from the third floor. He also said it turned pitch black inside the plant, and that he crawled through the rubble to safety.
About 50 Omaha firefighters battled the blaze and rescued five people from the rubble, Kanger said.
Representatives of the Bureau of Alcohol, Tobacco, Firearms and Explosives and the Occupational Safety and Health Administration (OSHA) were also at the scene.
The grain handling industry, which includes feed plants, is considered "high hazard," due partly to the risk of fires and explosions from the accumulation of combustible grain dust, according to the OSHA website.
Privately owned International Nutrition makes feed, vitamins and nutritional products for animals. (Editing by Ellen Wulfhorst, G Crosse and Eric Walsh)