IMDC informed via SnapRep car 1642 floorwas wet due to heavy rain. SMCR was informed to arrange cle aner to dry affected area. Subsequently, CE happened to be o nboard T412 car 1642 called and informed the wet floor was q ~~~~~ Train was cleared by BSD on 03/03/23. CE: T412 (3642), FM1 (1642) found #2 end ceiling water leaking badly due to heavy rain. Floor very wet may cause tripping.     Check and found evaporator heavy icing, drain pan full of water    and evaporator left side drain pipe inner crack, cause alot water leak through saloon ceiling panel. Replace #1642-a/c 2 evaporator and function test ok. #1642-a/c 2 evaporator: Old: 536063. New: 331056. Not: 2467363 raised to CSC. Done by Sanip/Koh. 03/03/23.