Kind hard to heal the raid with 2 healers and your tank having 2 adds and 2 double ice blocks and thus no cooldowns while the main tank and rest of the raid continue to take damage. He took 11,489 damage per tick, each second for 8 seconds straight, while receiving 13,704 damage from the guardians (average). That is 105,616 damage in 8 seconds, which would require 13,202 HPS in order to heal through, not including cooldowns (which were already used). Realistically, another one of KTs stupid, 'haha I'm going to find a way to kill you' things.
He's the bane of our guild runs. We *finally* got Immortal after repeated wipes on KT in previous weeks. For instance... I was mind controlled and I DnD'd and Howling Blasted the entire melee range at about 5% on KT. Needless to say... melee died.