LACROSSE EVENT OPERATION REDWING 1, The atomic device, LACROSSE, was detonated at 0675, 5 May 1956 at the surface on the island of RUNIT in the ENIWETCE Atoll. The LACROSSE cloud reached an altitude of approximately 1C,000 feet, The cloud sheared at epproximately 18,000 feet with the ster. and lower portion of the cloud moving West, the upper portior roving to the Northeast. The initial helicopter survey indicated thet the fallout was developing as forecast. coal Based on the initial nelicopter survey and aerial monitoring reports, reentry hour was esteblished as O7L5M, 5 May 1956. All RADEX notices were withdrawn at 1210M, 5 May 1956 and the ENIWETOK area was open tc aircraft. 2. DNA The fallout prediction for LACROSSE was based or. 2 surface burst with a maximum yield on the order 0: The forecast * fallout plot (see TAB B). shows the fallout falling to the Northeast with long axes lying along a true bearing of 50°, The rether limited information on fallout for LACROSSE prevents a quantitative comparison of the actual and forecast patisarns, fo Fateawanvas Corin; oC ms SERIES—A ——_