Sokka knew he had a terminal disease for a long time. He had resigned from the Republic City council saying he “just wanted to take early retirement so he could spend more time with Suki.” A few months after his retirement, there came a night where Sokka knew he didn’t have long. He looked to his night-stand, where he had always kept his trusty boomerang — the weapon he always had ready in case he needed to protect his wife. “Well boomerang, it looks like one of us won’t be coming back.”
The following morning, Sokka had slipped away from the physical world.