Two construction workers who were laying concrete blocks at Ohio Fresh Eggs were killed in one of the barns, said Bill Schwaderer, a spokesman for the Ohio Department of Agriculture. Three other workers escaped with minor injuries.
Authorities blamed the barn collapses on high winds. The National Weather Service said the area, about 25 miles northeast of Columbus, was hit by a line of strong thunderstorms with winds estimated at 60 to 70 mph.
Strong winds also blew down a 10-foot-high brick wall at a school construction site in Edgerton, near the Ohio-Indiana state line, killing a worker, and knocked three semitrailers onto their sides on a highway in central Ohio.
The barns at Ohio Fresh Eggs, which produces about 5 million eggs per day at operations in three counties, had been empty of hens for several years and were being renovated, Schwaderer said. Water and electricity had been turned off for the renovation.
The barns were at least 15 years old, Monroe Township fire Chief Dudley Wright said.
The metal roof of the barn where the two men died was twisted like a roller coaster track. Another mangled piece of roofing blew across the road and landed in a cornfield.
Authorities closed the long country road leading to the barns, causing a backup of trucks headed to other farms.
The two construction workers who were killed were employed by an outside contractor, not by the farm, Ohio Fresh Eggs spokeswoman Hinda Mitchell said.
Licking County Sheriff Randy Thorp identified them as 25-year-old Kevin Maddox and 33-year-old Joseph Dixon.
Dixon had two daughters, ages 5 and 9, and was planning to get married next month, said his fiancee, Carrie Loudermilk, 34, of Newark. The couple lived together and had been dating for more than two years.
Dixon worked for Creative Masonry for more than a year and has been renovating barns at the farm as a contractor for about a month, Loudermilk said.
It wasn't clear whether both victims worked for Lancaster-based Creative Masonry. A man who answered the phone there late Tuesday hung up on a reporter seeking comment.
The deaths were the third at Ohio Fresh Eggs in less than a year. A worker died at a different facility in September when he fell from a ladder inside a grain bin.
A fire in March killed more than 250,000 hens at its farm in Marseilles, about a 90-minute drive northwest of Croton.
Investigators ruled out arson but didn't come up with a cause. Ohio Fresh Eggs has a history of clean-water law violations and complaints from neighbors about fly and rodent infestations.
The Department of Agriculture revoked the farm's permits to operate in 2003, but an appeals panel later reversed that decision. The U.S. Environmental Protection Agency last year fined the company $300,000 for illegal water pollution.
Associated Press writers Matt Leingang, Julie Carr Smyth and JoAnne Viviano in Columbus and John Seewer in Toledo contributed to this report.