A grisly murder has led to Alaskas annual Fat Bear Week being postponed.

The battle to be the plumpest predator was delayed after a younger male brown bear killed an older female while hunting for salmon on Monday morning.

The violent death of the matriarch known as 402 was captured on a livestream from Katmai National Park and Preserve, which serves as a prime feeding spot for animals hoping to pack on as many pre-hibernation pounds as possible before winter.

Viewers watched as 402 and her assailant, 469, ferociously sparred until she was overpowered and sunk into the waters of the Brooks River.

469, whose distinctive blond mark on his shoulder earned him the nickname Patches, then began eating his fallen adversary, later dragging her lifeless body out of the cameras view.

While Katmai ranger Sarah Bruce told The Washington Post she was unsure what exactly caused Mondays carnage, she said, Its not unusual for bears to eat one another if the opportunity arises.

Both 402 and Patches had been familiar to Katmai rangers for more than 20 years, but only 402 had ever been in the running for fat bear supreme.