▁were ▁partially ▁covered ▁and ▁the ▁tr ams ▁were ▁given ▁a ▁grey ▁cam ou fl age . ▁Due ▁to ▁the ▁fuel ▁short age , ▁tr uck ▁operations ▁were ▁restricted ▁during ▁the ▁war ▁years , ▁so ▁tr ams ▁carried ▁mail ▁between ▁Kar ls ru he ▁station ▁and ▁the ▁main ▁post ▁office ▁as ▁well ▁as ▁fruit ▁and ▁veget able ▁ship ments ▁from ▁the ▁market ▁hall ▁to ▁various ▁ret ail ers . ▁As ▁in ▁the ▁First ▁World ▁War , ▁passenger ▁numbers ▁also ▁rose ▁consider ably ▁during ▁the ▁Second ▁World ▁War , ▁reaching ▁ 6 6 ▁million ▁passengers ▁in ▁ 1 9 4 3 . ▁The ▁tram ways ▁were ▁dam aged ▁by ▁a ▁bomb ing ▁ra id ▁in ▁ 1 9 4 1 ▁and ▁the ▁tram ▁network ▁was ▁closed ▁ 1 9 4 4 ▁by ▁massive ▁ra ids ▁and ▁could ▁only ▁be ▁partly ▁restored ▁to ▁operation . ▁A part ▁from ▁the ▁damage ▁to ▁the ▁network , ▁two ▁tram c ars ▁and ▁three ▁tra ilers ▁were ▁destroyed . ▁ ▁After ▁the ▁occupation ▁of ▁Kar ls ru he ▁in ▁April ▁ 1 9 4 5 , ▁the ▁tram ▁service ▁was ▁gradually ▁brought ▁back ▁into ▁operation . ▁By ▁ 1 9 5 0 , ▁the ▁reconst ruction ▁was ▁complete , ▁although ▁some ▁brid ges ▁had ▁been ▁given ▁only ▁temporary ▁rep airs . ▁The ▁carriage ▁of ▁fruit , ▁veget ables ▁and ▁mail ▁by ▁tram ▁ended ▁with ▁the ▁normal isation ▁of ▁conditions . ▁ ▁Modern isation ▁and ▁expansion ▁▁ ▁So on ▁after ▁the ▁Second ▁World ▁War ▁a ▁struct ural ▁change ▁occurred ▁in ▁an