NEW YORK - (AP) ? Stocks plunged again Wednesday as investors turned their attention back to the weak economy and Europe's debt problems. Most of the big gains that followed a Federal Reservepledge to extend super-low interest rates vanished. The Dow Jones industrial average fell 520 points, or 4.6percent, to 10,719. The S&P 500 fell 52, or 4.4 percent, to 1,120,and the Nasdaq fell 101 points, or 4.1 percent, to 2,381. On Tuesday, the Dow gained 429 points after the Fed said itplanned to keep interest rates extremely low at least through themiddle of 2013.

Dow rallies after Fed statement, up 429 points Wall Street takes a dive on first day after downgradeU.S. downgrade raises anxiety, if not interest ratesS&P downgrades U.S. credit rating from AAA