TORONTO - North American stock indexes plunged steadily throughout the trading session on Thursday, with losses on the Dow Jones industrial average and the Standard & Poor 500 entering correction territory. In New York, the Dow was down 1,032.89 points, or 4.15 per cent, to 23,860.46, and the S&P 500 index was down 100.66 points, or 3.75 per cent, to 2,581.00. The Nasdaq composite index was down 274.82 points, or 3.90 per cent, to 6,777.16. ...