BSE Sensex index on Friday tanked 3,090.62 pts to 29,687.52 in the opening session. Nifty 50 index plunged 966.10 pts to 8,624.05. As Sensex and Nifty hit lower circuit limits, stock exchanges have halted trading for 45 minutes. Meanwhile, Rupee has slipped 16 paise to 74.44 against US dollar in early trade as coronavirus panic worsens.