The Sensex at the Bombay Stock Exchange plunged 365 points, or 2.3 percent, to once again close below the 16,000 mark, at a more than two-year low of 15,700 on Wednesday.The Sensex fell on heavy fund outflows, amid weak Asian and European markets, and global growth worries. The Nifty at the National Stock Exchange declined 106 points, or 2.2 percent, to 4,706.Stock markets in China , Hong Kong , South Korea and Singapore lost between 0.7 percent and 2.4 percent.