U.S. stock futures drop as Japan crisis worsens
March 15, 2011 at 05:46 AM EDT
* U.S. stock index futures dropped sharply on Tuesday, with futures for the S&P 500 down 2.8 percent, Dow Jones futures down 2.5 percent and Nasdaq 100 futures down 2.6 percent at 0935 GMT, on mounting fears over Japan's nuclear crisis.
