This paper presents genetic algorithm based post-outage voltage calculations and screening for transmission line and transformer outages. Deficiencies of the traditional sensitivity based (linear) methods are overcome by formulation of a line outage as non-linear constrained optimization problem for a bounded network. The proposed optimization problem is later solved for bounded network variables by genetic algorithms, GAs. The accuracy of the method is tested on IEEE IEEE 57-bus test systems. The results are compared with those obtained by a fun load flow to verify the strength of the paper.