Envelope reads "Hetch Hetchy Mitchell tunnel explosion 7/18/30." Photograph was printed in the Oakland Tribune on July 18, 1930 with the caption "Rescue team sleeping on lumber piles at shaft top waiting for word that poison gas has been cleared from death tomb so they may search for bodies." Photograph shows a group of men sleeping under blankets. What appears to be a train track is visible in the foreground. Lumber and sandbags form the background." For more information about the Mitchell explosion see h99.1.482.