There is no definitive cause of a fire that killed more than 60 cows last week on a southwest Michigan dairy.

“We had the state fire marshall out there and he couldn’t get a cause on it; there was so much damage,” a spokesman for the Buchanan Township Fire Department told Dairy Herd Network. “So, we ruled it undetermined, accidental.”

Several structures were a total loss.

“This is our livelihood,” a shaken farm owner, Nick Powers, told ABC 57 News. To see a video report from the South Bend, Ind., television station, click here.

After the fire broke out, Powers said efforts were made to get into the barn to let the cows out, “but we couldn’t make it.”