Sokka Death Theory
We know that Sokka outlived Aang because he knew Korra when she was little, but we don’t know when or how he died. I think it was Zaheer and the Red Lotus. If you think about how much work went it to those prisoner specific cells that were spread around the world (P'li in the ice cave, Ming Hua in the volcano) and to have White Lotus guards on them all the time. Ozai didn’t even have that much security, granted he didn’t have his bending but still. What did they have to do in order to have that steep a punishment? I think it was Tonraq that told about the Red Lotus trying to kidnap Korra when she was little, that Chief Sokka had a part in saving her. That’s when he died. The Red Lotus killed him during the attack, Korra and Tonraq got away. He died fighting. He died a hero.