Wall Street declined on Tuesday with the benchmark indexes S&P 500 and Nasdaq closing lower and the Dow Jones failing to close above a level of 16,000 after Carl Icahn commented the situation on global equity markets. The Standard & Poor's 500 Index slid 0.37% to 1,791.53, the Nasdaq Composite Index fell 0.93% to 3,949.07, while the Dow Jones industrial average gained 0.09% to 15,976.02.