Falling for the fourth straight session, the Sensex at the Bombay Stock Exchange dropped 127 points, or 0.8 percent, to 16,293, on disappointing industrial output data, and amid falling Asian and European markets, today. The Sensex had lost almost 500 points in the previous three trading sessions. The Nifty at the National Stock Exchange lost 37 points, or 0.7 percent, to 4,929.Stock markets in Japan, China, Hong Kong, Singapore and South Korea declined between 0.6 percent and 1.4 percent .