West, who didn't perform in the one-hour special, was on the stage with comedian Mike Myers reading a script from the teleprompter when he deviated from the pre-written dialogue to attack Bush and the government's reaction to Hurricane Katrina.
He ranted, "If you see a black family it's looting but if it's a white family they are looking for food... We realise that a lot of people who could help are at war fighting another way (but) now they have given them permission to go down and shoot us."
But the biggest shock of all came when West stated, "George Bush doesn't care about black people," prompting the camera rapidly cut away to stunned comedian Chris Tucker, who stumbled through his lines.
There was a tape delay, but the censor was listening for profanity and didn't realise West was not following his script, according to NBC bosses.
West's final comment was edited out of the West Coast airing of the show, which was broadcast three hours later.
In a statement, NBC says, "Kanye West departed from the scripted comments that were prepared for him, and his opinions in no way represent the views of the networks.
"It would be most unfortunate if the efforts of the artists who participated tonight and the generosity of millions of Americans who are helping those in need are overshadowed by one person's opinion."