Applying ideas in earthquakes that cause the most damage, at what depth would movement along a fault most likely occur?

About 90% of all earthquakes have depths < 100 km. Earthquakes can be grouped into three categories based on the depth of their foci:

Shallow focus - Foci are less than 70 km depth. Most destructive earthquakes.

Intermediate focus - Foci are between 70 and 300 km depth.

Deep focus - Foci are greater than 300 km.