New York, Sept. 7 (BridgeNews) - The Dow industrials plunged more than 200 points and the Nasdaq composite index fell to its lowest level since April 6 after the unemployment rate rose to a four-year high of 4.9% in August. The Dow Jones industrial average closed down 234.99, or 2.39%, to 9605.85 and the Nasdaq Composite index was down 17.95, or 1.05%, to 1687.69. The S&P 500 was down 20.62, or 1.86%, to 1085.78--its lowest closing level since Oct. 28, 1998.