Those defenses were of the “spider web” type to which there were many entrances. They were constructed by knocking out the heads of empty gasoline drums and making an impromptu pipeline of them, sunk into the ground and covered with earth and palm fronds. The tunnels thus constructed branched off in several directions from a central pit and the whole emplacement was usually concealed with great skill and ingenuity. If the main position was spotted and attacked the riflemen within could crawl off fifty feet or so down one of the corridors and emerge at an entirely different and unexpected spot from which they could get off a shot and dive down to concealment before it was possible to determine whence the fire proceeded. Every foot of ground had to be gone over with the greatest precaution and alertness before these honeycombs of death could be silenced by the literal process of elimination. The attacking Marines soon hit upon a method of destroying completely these underground defenses. When the bunker at the center of the web had been located, a member of the assault team would hurl a smoke grenade inside. Although this type of missile did no harm to the Japanese within, it released a cloud of vapor which rolled through the tunnels and escaped around the loosefitting covers of the foxholes. Once the outline of the web was known, the bunker and all its satellite positions could be shattered with demolitions. ] [Sidebar (page 28): The Secretary of the Navy Washington The Secretary of the Navy takes pleasure in commending the Twenty-Second Marines, Reinforced, Tactical Group One, Fifth Amphibious Corps consisting of Twenty-second Marines; Second Separate Pack Howitzer Company; Second Separate Tank Company; Second Separate Engineer Company; Second Separate Medical Company; Second Separate Motor Transport Company; Fifth Amphibious Corps Reconnaissance Company; Company D, Fourth Tank Battalion, Fourth Marine Division; 104th Field Artillery Battalion, U.S. Army; Company C, 766th Tank Battalion, U.S. Army; Company A, 708th Amphibian Tank Battalion, U.S. Army; Company D, 708th Provisional Amphibian Tractor Battalion, U.S. Army; and the Provisional DUKW Battery, Seventh Infantry Division, U.S. Army. for service as follows: