▁mid - Dec ember ▁ 2 0 0 1 , ▁although ▁the ▁system ▁remained ▁dis organ ized ▁for ▁more ▁than ▁a ▁week . ▁The ▁storm ▁gradually ▁m ature d ▁and ▁att ained ▁tropical ▁cy clone ▁status ▁on ▁December ▁ 2 9 . ▁Sub sequently , ▁W aka ▁under w ent ▁rapid ▁intens ification ▁in ▁which ▁it ▁att ained ▁its ▁peak ▁intensity ▁as ▁a ▁Category   4 ▁severe ▁tropical ▁cy clone ▁( Austral ian ▁tropical ▁cy clone ▁intensity ▁scale ) ▁on ▁December ▁ 3 1 , ▁with ▁wind s ▁of ▁ 1 8 5   km / h ▁( 1 1 5   m ph ). ▁Short ly ▁there after , ▁it ▁passed ▁directly ▁over ▁V ava ʻ u , ▁T ong a , ▁resulting ▁in ▁w ides p read ▁damage . ▁By ▁January ▁ 1 , ▁ 2 0 0 2 , ▁the ▁cy clone ▁began ▁to ▁weak en ▁as ▁it ▁under w ent ▁an ▁extr at rop ical ▁transition . ▁The ▁rem n ants ▁of ▁W aka ▁pers isted ▁for ▁several ▁more ▁days ▁and ▁were ▁last ▁observed ▁near ▁the ▁Southern ▁Ocean ▁on ▁January ▁ 6 . ▁ ▁Although ▁the ▁storm ▁affected ▁several ▁countries ▁along ▁its ▁path , ▁W aka ▁left ▁the ▁most ▁significant ▁losses ▁in ▁T ong a , ▁where ▁it ▁killed ▁one ▁person ▁and ▁wr ought ▁ 1 0 4 . 2   mill ion ▁pa ʻ anga ▁($ 5 1 . 3   mill ion ▁US D ) ▁in ▁damage . ▁H undred s ▁of ▁structures , ▁including ▁ 2