Drone Video: Killer whales attack gray whale calf in Monterey Bay

Drone footage shows the moment when five killer whales attacked and killed a gray whale calf in the Monterey Bay as its mother tried relentlessly to offer protection.

According to Monterey Bay Whale Watch, the calf and its mother were on their migration Saturday, heading north to Alaska when they were attacked.

A group of killer whales pounced on the pair as they were making journey across the dangerous Monterey Submarine Canyon.

"This area is one of the most dangerous parts of their long migration from Mexico to Alaska as Killer Whales frequent Monterey Bay during the gray whales' spring migration and patrol the canyon edges looking for them," according to Monterey Bay Whale Watch.

Monterey Bay Whale Watch says the calf fought hard, but the Killer Whales continued to ram the young animal to try to separate it from its mother.

"This predator/prey interaction is a harsh fact of nature and the whale watchers were in awe as they experienced their own "National Geographic moment' in person," said a spokesperson for Monterey Bay Whale Watch.

The attack lasted for about four hours.