Much of the rehabilitation was performed in Japan, with initial preparation in the combat area itself supported by Korean locals in addition to US personnel. Vehicles were deconstructed, cleaned with chemicals or rebuilt to be made functional, tested to ensure functionality (including test drives through an obstacle course), and shipped to the front lines as quickly as possible. For example, 52 hours after Marines were ambushed in Chosin, a complete set of equipment required to rearm the unit was shipped to the front lines. Ultimately, 45 percent of the tanks, 82 percent of armored cars, and 75 percent of the artillery used in the conflict were recovered equipment left behind after the end of Pacific operations in WWII.