Tourists and a helicopter pilot this week discovered at least 50 dead whales that had washed up on a beach in Iceland, according to The Associated Press.

David Schwarzhans, a pilot for Reykjavík Helicopters, told the AP on Friday that he and his passengers counted the long-finned pilot whales on the Snaefellsnes Peninsula in western Iceland on Thursday.

{mosads}“Some were already buried in sand,” he said, adding that the whales were concentrated in one spot in what he described as “a very sad scene.” 

It is suspected that the whales swam ashore as a group and died of dehydration. Marine biologist Edda Elísabet Magnúsdóttir told the Iceland Monitor that the whales likely became disoriented in the shallow waters.

The pilot whale is known for stranding in large numbers, though the reasons are not entirely understood.

Locals were successful in turning away a group of whales last year from nearly beaching at a spot on the opposite side of the peninsula, according to the AP.