This paper deals with the electromagneto-elastic problem of a conductor with a finite crack under an impulsive electric current flow and a constant magnetic field. The crack disturbs the current flow and anti-plane shear stresses are caused by the interaction between the magnetic field and the disturbed current. Laplace and Fourier transforms are used to reduce the electromagnetoelastic problem to a Fredholm integral equation of the second kind in the Laplace transform plane. A numerical Laplace inversion routine is used to recover the time dependence of the solution. Numerical results on the dynamic stress intensity factor are obtained and are presented in a graphical form.