Mauna Loa's 1942 eruption occurred only four months after the attack on Pearl Harbor and the United States' entry into World War II, and created a unique problem for the wartime United States. Occurring during an enforced nighttime blackout on the island, the eruption's luminosity forced the government to issue a gag order on the local press, hoping to prevent news of its occurrence spreading, for fear that the Japanese would use it to launch a bombing run on the island. However, as flows from the eruption rapidly spread down the volcano's flank and threatened the ʻOlaʻa flume, Mountain View's primary water source, the United States Army Air Force decided to drop its own bombs on the island in the hopes of redirecting the flows away from the flume; sixteen bombs weighing between each were dropped on the island, but produced little effect. Eventually, the eruption ceased on its own.