Envelope reads "Hetch Hetchy Mitchell tunnel explosion 1930." In the center of the frame is a man wearing suit pants, an open vest, and a hat pointing at something out fo the frame to the left. He looks to where he points. To the right of the first man stands a second wearing a suit with vest, jacket, watch chain, and hat. He has his hands in his pockets. He looks where the first man is pointing. A few other figures can be seen in the background to the right of the frame. For more information about the Mitchell explosion see h99.1.482.