Killer whales eat fish, sharks, seals, dolphins, other smaller and larger whales, polar bears, moose, etc etc basically anything that swims or is capable of swimming. Except humans. There has never been a recorded human attack. Sharks are known to attack people when they look like their prey, ie seals, so why not killer whales? They wouldn't have any problems killing a person; just look at how they kill seals.
Dead seal
Now, if we switch the seal with a human...
Dead person
See, they wouldn't have any problems killing people.
Dead seal
Now, if we switch the seal with a human...
Dead person
See, they wouldn't have any problems killing people.