News at Seven-Thirty highlights: a probable case of H1N1 influenza infection in Hong Kong; WHO stopped using the term swine flu and will now call the virus H1N1; Mexican officials say the spread of the flu virus appears to be slowing; a small chopper slammed into a coach at the old Kai Tak airport site; U.S. automaker Chrysler has filed for bankruptcy protection; Los Angela Police believed to have arrested one of the most prolific serial killer in the city’s history; all official Queen's Day festivities in the Netherlands were cancelled; several thousand people took to the streets to demand better rights for local workers; hundreds of people marched to the government headquarters in Macau; violent clashes have broken out during some May Day protests in Europe; Big Four accounting firms asked employees to take time off without pay or on reduced wages; Mainland authority has launched the one-year countdown to the Shanghai World Expo; thousands of people flocked to Cheung Chau today.