Does anyone know why coastal towns are at an especially high risk from an earthquake?

Tsunami's. Most town are situated along the "ring of fire".

One reason is tsunamis, which is the answer that everyone has been giving you, but that is not the whole story. Many coastal town are also built on land with a high water content, and under the extreme shaking of an earthquake the ground can actually become liquid, destroying the foundation of buildings. This was a source of much of the destruction in the large Anchorage, Alaska earthquake of 1964.

Coastal towns and cities are at an especially high risk from an earthquake because fault lines such as subduction zones are usually at the edge of continents. This is where earthquakes occur.

I lived on a coastal town. The quakes don't scare people, but the tidal waves terrify everyone.

because coastal towns are on the edges of continents and most tectonic plates roughly follow the shapes of continents. it is when plates "rub" past one another that earthquakes happen.

earthquakes can cause tsunamis

man , what school are you in ? after 2004 tsunami , everybody should know

no offense , i blame your teachers