Power system operators commonly rely on a security-constrained unit commitment (SCUC) to schedule available generation resources for satisfying the forecasted load and ensuring system security in response to limited components unavailability. Although widely used and proved viable, the SCUC problem cannot guarantee a useful solution in response to extreme events with potentially multiple outages. This paper proposes and formulates an Event-driven SCUC (E-SCUC) model which ensures a resilient supply of loads in case of multiple component outages. The new N-1-m reliability criterion, in which m is the number of components on outage due to the extreme event, is proposed and integrated with the model. A probabilistic estimation model of possible component outages is further investigated. The E-SCUC problem is formulated using mixed-integer linear programming (MILP). Merits and effectiveness of the proposed models are demonstrated using the standard IEEE 30-bus system. Comparing the results of the E-SCUC with the SCUC demonstrates the resiliency benefits of the proposed model as it ensures a considerably lower load curtailment at the expense of nominal cost increase.