On June 25, 1997, a Russian Progress M-34 spacecraft collided with the Russian Mir space station. [βOn This Day in Spaceβ Video Series on Space.com]
The uncrewed cargo spacecraft was doing an experimental test of the docking system when it crashed into the space station's Spektr module. The collision ended up puncturing Spektr's hull, causing a slow leak and damaging one of its solar panels. The crew had time to prevent depressurization of the Mir station by installing a hatch cover.