The Sensex is now down 646 points at 15,115.The NSE Nifty is down 175 points at 4,571.HDFC has tumbled over 10% to Rs 2,245. ICICI Bank has slumped 7% to Rs 816.Jaiprakash (JP) Associates has plunged 6.8% to Rs 220. Ranbaxy, Tata Steel, DLF and Reliance Communications have dropped over 5.5% each to Rs 438, Rs 676, Rs 619 and Rs 490, respectively.HDFC Bank has slipped over 5% to Rs 1,247. Reliance Energy and Hindalco have shed around 4.5% each at Rs 1,238 and Rs 174, respectively.SBI, Bharti Airtel and Reliance are down around 4% each at Rs 1,642, Rs 723 and Rs 2,231, respectively.