US stocks plunged on Tuesday, driving the Dow Jones industrial average down in its worst slide since the aftermath of the 9/11 attacks, as a sell-off in China raised concerns about high equity valuations.The selling was so intense that it wiped off nearly $600bn in market value for the day. The closing bell on NYSE was greeted with a chorus of "boos" from the floor.While the Dow average slipped 416 points (3.29%) to end at 12,216, the Nasdaq Composite plunged 97 points (3.86%) to 2,408.
