Falling for the third straight session, the Sensex at the Bombay Stock Exchange slumped 253 points, or 1.6 percent, to close below the 16,000 level after a week, at 15,965, today, as the global markets declined amid a deepening euro zone debt crisis. The Sensex had lost 220 points in the previous two trading sessions. The Nifty at the National Stock Exchange slipped 83 points, or 1.7 percent, to 4,842. Stock markets in Japan, Hong Kong, South Korea and Singapore declined between 0.4 percent and 1.2 percent.