Naxxramas LoreEdit

Where exactly in official lore that Naxxramas was moved to Northrend, "unbeknown" to The Argent Dawn? Also, though Kel'Thuzad survived his first defeat, did lore state that he was killed at his second defeat, or is this speculation? Kanariya (talk) 20:47, August 29, 2010 (UTC)