Falling for the fourth straight session, the Sensex at the Bombay Stock Exchange plunged 388 points, or 1.9 percent, to close well below the 20,000 level, at 19,674, on Thursday. The market fell on across-the-board selling pressure, as the global markets lost ground on concerns that the US central bank may soon wind down stimulus measures, if economic conditions improved. The Nifty at the National Stock Exchange plummeted 127 points, or 2.1 percent, to 5,967.Stock markets in Japan, China, Hong Kong, Singapore, and South Korea slipped between 1.1 percent and 7.3 percent. Key European markets in the UK, France and Germany had lost over 2 percent each, in intra-day trade.