Casey and some members of his staff came ashore on A-Day; the advance echelon of his ASCOM headquarters arrived two days later. Work began immediately on the airfield at Tacloban, and commenced on airfields in central Leyte soon after they were captured. Heavy seasonal rains thwarted attempts to develop the airbases in central Leyte and it was decided to abandon their development and construct a new airbase on the coast at a site occupied by Sixth Army headquarters. The need to get aircraft based on Leyte to stop the Japanese from reinforcing the island was so pressing that Lieutenant General Walter Krueger agreed to move his headquarters.