While mining the approved stope sequence in the 100/900 ore bodies at the North Mine in Sudbury Basin of Vale Inco Ltd and following a crown blast in one of the stopes in 100 orebody in a sill pillar area, several major seismic events, with the highest magnitude of 3.8 Mn (Nuttli), occurred in both the Trap Dyke, which is located between 100 and 900 ore bodies, and in the sill pillar itself. This paper describes the mechanism of these events and the methodology of designing highly yielding ground support for rehabilitation areas with a view to withstand future seismic impact. A risk-based systematic approach was developed to determine where enhanced support is required in any other areas to be exposed by future seismic activities.