This paper focuses on survivability modeling to characterize the transient behavior of an infrastructure-based wireless network in the presence of disastrous failures and repairs. Two modeling approaches, an exact model and an approximate product-form model are presented. Numerical experiments with the two models demonstrates that the approximative product-form approach obtain close to exact results with a significant lower computational complexity. The product-form approach has been applied to study the impact of various system parameters on the survivability of the studied network.