A water main break and an ammonia leak occurred as well at the facility.
The roof collapse ruptured pipes carrying ammonia releasing a plume of gas. While 11 people were evaluated for gas exposure, only three were removed to Henry County Hospital for minor injuries.
NAPOLEON -- Eleven people were evaluated for exposure to ammonia fumes today when a roof collapsed at a cold storage facility, causing a pipe to burst and release the gas.
Of the 11, three workers were transported to Henry County Hospital in Napoleon, where they were released.
Napoleon Police Chief Robert Weitzel said snow likely caused the roof at the Cloverleaf Cold Storage to collapse. Some area businesses temporarily evacuated employees but the area has since been cleared.
The collapse was reported just before 1 p.m. in the building's loading dock area at the plant, 1165 Independence Dr.
Denise Keller, assistant area director of the Occupational Safety and Health Administration's Toledo Area Office, said OSHA is investigating.
"We are on the scene," she said, noting it is "very early" in the investigation.
"Super heavy" wet snow that had built up on the roof over a loading dock caused the roof over that area to collapse, said Adam Feiges, a company official. There was no damage to the warehouse, and portions of the facility are expected to be up and running again by Friday, he said.
There were no effects on product caused by an ammonia release, he said, and a damage estimate is not yet known.
About 100 people work at the facility.
In a statement, he said the collapse caused a small, quickly contained release of ammonia. This release was immediately reported to all relevant federal, state, and local officials.
The damage to the facility is limited to a loading dock servicing a production room. The attached cold storage warehouse is undamaged and the limited release of ammonia did not occur within the warehouse itself. The loading dock servicing the warehouse is undamaged.
As part of the standard operating procedure, the refrigeration control system automatically cut off power to the facility, but temperatures within the warehouse are well below minimum safe requirements and it is anticipated that power to the refrigeration system will be restored soon, according to a company statement.
The insulated warehouse is designed to hold temperatures for a number of days under summer ambient temperatures.
The Napoleon facility is one of four Farmers Produce sites, a division of Cloverleaf Cold Storage, specializing in meat fabrication and packaging services focused on short runs and custom designed processes.
These services are provided in dedicated facilities staffed by meat and poultry professionals, according to the firm's Web site. Other Farmers Produce locations are in Iowa, Missouri, and North Carolina.
According to its Web Site, "Cloverleaf Cold Storage brings decades of experience and a relentless focus on customer satisfaction to every service that we provide. Our Farmers Produce division provides custom designed processing and packaging services to the meat industry."
The Web site lists 15 cold storage warehouses, four food grade ambient temperature warehouses, and four custom food processing facilities.