PORT-AU-PRINCE, HAITI -- In the hours and days after the city crumbled and the enfeebled government of Haiti disappeared from public view, a remarkable thing happened here: The police showed up for work. Since the earthquake struck, the once notoriously corrupt Haitian National Police have been doing their jobs and are keeping something approaching law and order in a capital of chaos. A force previously dominated by thugs has transformed itself, according to international advisers, U.N. police officers and Haitians. In Port-au-Prince today, there is something almost heroic about an officer trying to direct traffic on Grand Rue Dessalines.