US stocks tumbled on Tuesday in a global selloff as fears that Japan's nuclear power crisis could turn into a larger catastrophe sent investors in search of safety. In a second straight day of losses tied to Japan, the S&P 500 fell to within four points of support at 1,257, which was its 2010 closing level. The US benchmark index began trading down more than 2 percent and the Nasdaq composite index briefly turned negative for the year.
The Dow Jones industrial average was down 193.79 points, or 1.62 percent, at 11,799.37. The Standard & Poor's 500 Index was down 20.56 points, or 1.59 percent, at 1,275.83. The Nasdaq Composite Index was down 44.92 points, or 1.66 percent, at 2,656.05.