Billy Joel BOTCHES 'WE DIDN'T START THE FIRE' 'One of My Worst Songs Ever'

3/14/2014 6:58 AM PDT
Breaking News

Billy Joel HATES "We Didn't Start the Fire" ... at least he sure made it seem that way during a concert in Toronto, when he screwed up the lyrics and then RIPPED the song apart. 

The Piano Man was performing at the Air Canada Centre on March 9 when he tripped up over the lyrics right around the time he was supposed to sing about Rosenberg's H-Bomb.

That's when he stopped the band dead in their tracks ... and went off -- saying, "All you gotta do is f**k up one word in that song and it's a train wreck."

On the video, unearthed by, Joel continued to gripe, "It's the same thing verse after verse ... Just the words change. It's one of the worst melodies I ever wrote." 

JFK ain't the only one blown away ...