Blood pooling in the deep, frothy waters off Western Australia alerted researchers to a grisly scene unfolding before their eyes back in 2019. Ahead, they saw a pod of killer whales attacking a blue whale, stripping it of flesh and exposing bone until eventually, the carcass sank. While such a bloody demise may be hard for some to stomach, the remarkable behavior on the part of the orca pod represented a significant one: the first-ever recorded instance of killer whales bringing down Earth’s largest animal.

Curious as to whether or not the ambitious hunt was a fluke (pardon the pun), the team led by Cetacean Research Centre (CETREC WA) continued monitoring the pod to see if they would do it again. Just a fortnight later, they did, this time forming a gang of many of the same members from the first attack and hunting and killing a blue whale calf. Then in 2021, they were at it again killing yet another calf. The murderous talents of orcas has now been published in the journal Marine Mammal Science.

As impressive apex predators that take on sharks (sometimes slicing out the liver) and several whale species, it was already known that orcas were ambitious and skilled hunters. However, prior to the sighting in 2019 nobody was quite sure if they were capable of killing blue whales, which as the largest animal that has ever lived can be over 33 meters (110 feet) long.

Orcas harassing and attacking blue whales wasn’t exactly news either, but researchers from Flinders University in Australia, say these three predation events are the first confirmed kills. At just 7-10 meters (23 to 32 feet) in length, it might seem like a gargantuan task for an orca, but these animals move in pods, sometimes nearing 100 members.

Orcas are also highly social and intelligent animals capable of complex communication, meaning they are able to synchronize attacks for the best outcome. The grueling process of taking down Earth’s largest mammal makes for difficult reading but is undeniably an impressive feat for a group of marine predators.

“At arrival we already noticed a substantial flesh wound on the top of its head with bone exposed,” said co-author and Flinders University PhD Candidate Isabella Reeves in a statement sent to IFLScience. “The dorsal fin was missing, no doubt bitten off by the killer whales.”

“Soon after, there was large chunks of skin and blubber stripped off the sides of the whale, the blue was bleeding profusely and was weakening, evident by its slow speed… Close to the end, a female animal lunged headfirst into the blue’s mouth, presumably to feed on the tongue, the whale weakened more and we did not see the carcass again.”

RIP, Big Blue.