Following a Mindlin's theory for the bending of thin plates, we consider the electromagnetoelastic problem of a conducting plate containing a through crack under a uniform electric current flow and a constant magnetic field. The current flow is disturbed by the presence of the crack and the twisting moment is caused by the interaction between the magnetic field and the distubed current. Fourier transforms are used to reduce the electromagnetoelastic problem to one involving the numerical solution of a pair of coupled integral equations. The problem concerning the electric current density field is solved exactly. The singular stresses near the crack tip are determined in closed form. Numerical results on the moment intensity factor and the shear force intensity factor are obtained and are presented in a graphical form.