We study dynamic fragmentation of metallic structures using the cracking particles method with obscuration zone. The cracking particles method is an efficient meshfree method for modeling dynamic fracture. Fracture is modeled by a set of crack segments. The cracking particles method does not require the representation of the crack topology. To avoid numerical fracture observed in discrete approaches, we employ obscuration zones proposed by Mott in his analytical work of fragmentation theory. We also study the influence of initial imperfections with different stochastic input parameters on the results.