Canadian hockey fans began booing the American national anthem at Bell Centre in Montreal when Team USA played there on Saturday — sparking three fights to break out in the first nine seconds of the game, which the US won 3-1 with Canadian Prime Minister Trudeau in attendance.

Chantal Kreviazuk, who performed the Canadian anthem prior to the 4 Nations Face-Off title game Thursday changed a lyric as a rebuke to President Trump's repeated remarks about making the country the 51st state.

Trump Takes Jab at Canada Over Becoming 51st State. U.S. President Donald Trump took a playful jab at Canada, joking about it becoming the 51st state of the United States while humorously suggesting it could keep "O Canada" as its national anthem.