A study of catastrophic degradation of InGaN/GaN laser diodes (LDs) is presented. Local damage on the aged LD is identified with the reduction of the electron beam induced current (EBIC) intensity. A pipe-shaped defect is observed in the particular damaged region by using the transmission electron microscopy (TEM) and scanning transmission electron microscope (STEM) technique. Diffusion of the contact metal along the defect is enhanced by the local electric field and high temperature. Catastrophic degradation of the LD happens due to burning of the local region.