The Dow and Nasdaq fell 1 percent in morning trading on Tuesday while the S&P added to its losses after a disappointing revenue miss from Alcoa Inc and a sell-off in commodities, coupled with Japan's upgrade of the severity of its nuclear crisis.

The Dow Jones industrial average <.DJI> was down 121.47 points, or 0.98 percent, at 12,259.64. The Standard & Poor's 500 Index <.SPX> was down 11.61 points, or 0.88 percent, at 1,312.85. The Nasdaq Composite Index <.IXIC> was down 27.50 points, or 0.99 percent, at 2,744.01.

(Reporting by Ryan Vlastelica, Editing by Chizu Nomiyama)