The Sensex opened with a positive gap of 16 points at 6,584. After crossing the 6,600-mark in early deals and hitting a high of 6,608, the index drifted into negative zone after the government issued a fresh tsunami warning. The index dipped to a low of 6,507 - a drop of nearly 100 points from the intra-day high - towards the closing bell. The Sensex finally finished with a loss of 45 points at 6,523.While 23 Sensex scrips declined with a volume of 1.07 crore shares totalling Rs 496 crore, seven advanced with a volume of 24 lakh shares for Rs 160 crore.Heavyweights slipped on profit-taking. ITC declined nearly 2% (Rs 25) to Rs 1,296. Infosys was also down Rs 25 at Rs 2,049. Reliance dropped Rs 8 to Rs 523. HLL was marginally lower at Rs 144. SBI, however, was up 2% (Rs 11) at Rs 633. Gujarat Ambuja was down Rs 7 at Rs 395. Grasim and ACC also declined.Satyam was down Rs 10 at Rs 404, and Wipro lost 7 Rs to Rs 746.Hindalco gained more than 2% (Rs 32) to Rs 1,446. HDFC Bank advanced 2% (Rs 9) to Rs 521. Hero Honda was up Rs 7 at Rs 566. BHEL gained Rs 4 to Rs 748. HPCL crossed the Rs 400-mark, and closed with a gain of Rs 2 at Rs 401.