Fire killed many thousands of pigs at a hog breeding farm in south-central Minnesota, authorities said.

The blaze started about 2:50 p.m. Saturday and spread to three of the five buildings at the Cougar Run operation, located about 4 miles east of Truman, according to the Fire Department.

Four employees on duty at the time escaped unharmed, said Fire Chief Dave Bentz.

The fire's cause has yet to be determined, but Bentz said there is "nothing to indicated anything suspicious" about the blaze.

"Early estimates place the damages into multimillions" of dollars, the department said in a statement.

Cougar Run is owned by Pipestone System of Pipestone, Minn., which also has operations elsewhere in Minnesota as well as in Iowa, Nebraska and South Dakota.

The blaze killed about 4,000 sows and 6,000 to 7,000 piglets, according to Pipestone System CEO Luke Minion. Another 1,300 sows were saved, Minion added.

Once investigators clear the site, the rebuilding process will begin, he said.

"A farm this size is going to take seven months [to rebuild]," Minion said. "It could be a year before producers can get back to normal pig flow."

Fire crews were on the scene until 10 p.m. Saturday, then returned twice Sunday "to hit some hot spots," Bentz said.

Nine fire agencies joined Truman's Fire Department at the scene. Four other emergency response agencies also assisted, as did members of the community providing food and water for all personnel on duty.

The Associated Press contributed to this report. Paul Walsh • 612-673-4482