Stocks fell at today's open as growing alarm about the sluggish US economy and weak corporate profits - coupled with a steep decline in European markets - sparked a flurry of selling.
Technology stocks led the retreat into negative territory and the tech-laced Nasdaq Composite Index slumped 71.84 points, or 3.57 per cent, to 1,942.94.
The selling was broad-based, and the Dow Jones industrial average tumbled 165.21 points, or 1.61 per cent, to 10,125.59.
The broader Standard & Poor's 500 Index fell 18.74 points, or 1.56 percent, to 1,178.92.
European stocks were hammered to their lowest levels since the start of November 1999 as Wall Street's gloom spread worldwide.
Investors' nerves were further jangled after a major international rating agency expressed concern about the financial health of more than a dozen Japanese banks.