LAKE MILLS, Iowa - Authorities say four people were treated for smoke inhalation after a fire broke out in a livestock building near Lake Mills in northern Iowa.

The building at J & R Livestock housed calves, and officials say an unknown number died in the fire Wednesday afternoon.

Lake Mills Fire Chief Dave Anderson told KIMT-TV of Mason City that straw in the building caught on fire, and the fire spread to small holding huts used to provide shelter for the calves.

Anderson says four employees suffered smoke inhalation when they tried to rescue the calves. The workers were treated at a medical center and released.

The cause of the fire remains under investigation.

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Information from: KIMT-TV, http://www.kimt.com

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