A Norwegian environment official came upon a sad sight on regular rounds last Friday: The bodies of 323 dead reindeer, clustered on a rocky hillside. A few were still breathing; he put them out of their misery.

The strange massacre happened, apparently, after the group was struck by lightning in a storm last week.

“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,” a government spokesperson told local media. “We don’t know if it was one or more lighting strike; that would only be speculation.”

How did they die, exactly? The idea of a single bolt striking the group is astounding, and yet it’s even less plausible that 323 bolts struck the same area, picking the animals off one by one.

While it’s pretty rare for a lightning storm for kill more than one human, there are reported cases of mass deaths in livestock. In 2009 a lightning strike killed 16 bulls in Scotland that had huddled under a tree to seek shelter from the storm. An eyewitness described the bolt hitting one of the cows, and others suspected that it had then traveled through the others standing in the same puddle.

Dead reindeer lay on a Norwegian hillside in the aftermath of a lightning storm.
Dead reindeer lay on a Norwegian hillside in the aftermath of a lightning storm.

In all likelihood, this is how the reindeer in Norway met their end, too. Imagine huddling for security and warmth, except you’re not wearing shoes and you’re up to your ankles in soggy tundra. Now the whole area you’re standing in is basically a bathtub that you just dropped a hairdryer into, and there’s nowhere left to hide.

This ground-up lightning strike is the sort that causes the most fatalities and injuries, because it has the potential to impact a much broader area than a direct hit, according to NOAA.

And our four-legged friends are much more vulnerable than humans: Imagine lightning traveling up one of your legs and down the other. Now imagine going down on all fours and the same thing, but now the lightning comes up your legs and out your hands. In the second scenario, the potential for the heat and electricity generated to fatally damage internal organs is much greater.

Officials have taken samples from the reindeer in hopes of solving this tragic mystery.

Photos via Håvard Kjøntvedt / Miljødirektoratet/Statens naturoppsyn, Havard Kjøntvedt / Miljødirektoratet/Statens naturoppsyn (1, 2)

Jacqueline Ronson is a science writer based on Vancouver Island, Canada. Before that she lived way up in Whitehorse, where she reported for the Yukon News. These days she likes to talk to smart people about the future of the planet, ride her bicycle, play her banjo, and frolic.