The Dow Jones industrials fell under 9,000 this afternoon for the first time since the summer of 2003 as investor confidence that markets would stabilize appeared to collapse. At 3:40 p.m. ET, the blue chips were down 641 points, or 6.9%, to 8,617. The Standard & Poor's 500 Index was off 74 points, or 7.5% to 911. The Nasdaq Composite Index was down 94 points, or 5.4%, to 1,646. The S&P fell under a closely monitored support level of 960. A support level is important because it is supposed to trigger new buying. At those levels, the crash of 2008...