The 1967 Koynanagar earthquake occurred near Koynanagar town in Maharashtra, India on 11 December. The 6.5 magnitude shock hit near the site of Koyna dam and claimed at least 180 lives and injured over 1,500. More than 80% of the houses were damaged in Koyana Nagar Township, but it didn’t cause any major damage to the dam except some cracks which were quickly repaired.

source: http://en.wikipedia.org/wiki/1967_Koynanagar_earthquake