BOMBAY -- Bombay stocks dropped 1.6% Friday as investors everywhere flee rising crude oil prices.The BSE Sensex index dropped 180 points to close at 10,678.22. The index has dropped three days in four, the exception being Wednesday's 3.1% snapback rally following Tuesday's apparent attacks on the city's rail system. Laggards on the index Friday were Hindalco, which lost 4%, Tata Motors ( TTM), down 3.9%, and Grasim, down 3.7%. Gainers were Hero Honda, which rose 1.1%, SBI, up 0.8%, and Reliance Energy, higher by 0.6%. HDFC Bank ( HDB) slid 2.5% even as it reported a 30% rise in its first-quarter earnings.