Mumbai : Profit booking, along with caution ahead of key global and domestic events and negative international indices, plunged the Indian equity markets on Tuesday. Consequently, the key indices provisionally closed the day’s trade deep in the red, as heavy selling was witnessed in automobile, healthcare and banking stocks. The wider 51-scrip Nifty declined by 45 points or 0.52 per cent to 8,590.65 points. The barometer 30-scrip sensitive index (Sensex) of the BSE, which opened at 28,121.37 points, provisionally closed at 27,949.89 points down by 145.45 points or 0.52 per cent from the previous close at 28,095.34 points.