The December 26, 2004 Sumatra earthquake of Moment Magnitude Mw KEYWORDS: Earthquake, Tsunami, Brick Masonry, Adobe Houses, Toppling of Roofs = 9.3, the largest earthquake in the world since the 1964 Prince William Sound, Alaska earthquake, generated a widespread tsunami. Soon after the earthquake, the authors visited Tamil Nadu and Pondicherry for a damage survey. This paper describes the structural aspects of damages caused on the coast of Tamil Nadu. The area covered was along the coast from Chennai on the east coast to Thiruvananthapuram on the west coast. There were practically no major evidences of damage due to direct shaking while damages due to tsunami were extensive. Both masonry and concrete structures were damaged, though level of damage varied. In general, structural damages involved: damage to brick masonry, damage to compound walls, collapse of adobe houses, failures of columns and toppling of roofs, damage due to lack of detailing of reinforcement. Causes of damages have been investigated and remedial measures to avoid those in a future tsunami are suggested. A good correlation between run-up height and level of damage is found.