A lightning strike at a park in southern Norway killed hundreds of reindeer, Gizmodo reports.

The website reports the Norwegian Nature Inspectorate (NNI) confirmed a body count of 323 reindeer, including 70 calves. Five animals were later euthanized.

“We’ve heard about animals being struck by lightning and killed, but I don’t remember hearing about lightning killing animals on this scale before,” spokesman for the Norwegian Nature Inspectorate Knut Nylend said, according to Sputnik.com. “We don’t know if it was one or more lighting strike; that would only be speculation.”

It’s reported heavy thunderstorms drilled the Hardangervidda region throughout Friday, and officials believe that’s what led to the reindeers’ demise. Officials also suggest the high rate of death came because the animals were huddled together, likely seeking shelter from the storm.

The Local Norway reports close to 10,000 reindeer migrate in the park, which makes it Norway’s largest wild reindeer range.