Evidence that killer whales take care of their own, from the Russian Orcas Facebook page:
There have been several reports from around the world about disabled killer whales surviving through the help of their family members. This summer we have encountered this female that obviously had some problems with her back. She was swimming slowly behind the group, and one male always stayed near her. Despite her disability, she did not look skinny, suggesting that she might get food from her family members.
The Earthist Chronicles 