The benchmark Sensex on Friday tumbled more than 509 points to go below 15,000 mark in morning trade on heavy selling by funds following a meltdown in global markets on fears about a spreading credit crunch.
The BSE-30 shares index, which had closed down by 207.83 points on Thursday, lost another 509.82 points, or 3.38 per cent at 14,590.33 in the first five minutes of trade.
Similarly, the National Stock Exchange's Nifty plunged 164 points, or 3.07 per cent at 4,239.20.
Stock brokers said reports that French BNP Paribas has frozen accounts of three mutual funds triggered panic selling by funds.
All the BSE-30 index and Nifty-50 stocks were in the red with steep falls.