ZURICH (AFP) - The death toll in Haiti from Tropical Storm Hanna has exceeded 500 and is growing by the hour, the UN's Office for the Coordination of Humanitarian Affairs said Saturday. "The toll is increasing hourly," an OCHA official told AFP, adding that "according to information from the government (in Port-au-Prince) we have reached more than 500 deaths." Previous reports said at least 163 people had been killed during the passage of Hanna, which deluged Haiti early this week just eight days after Hurricane Gustav caused around 77 deaths. Tropical Storm Fay two weeks ago killed another 40 people in Haiti, the poorest nation in the Americas with 70 percent of its people living in poverty and mountainous terrain prone to mudslides. The worst-hit city was Gonaives, Haiti's third largest, which was flooded after being hit by Hanna Monday and Tuesday, leaving some 200,000 people with little food or water since the storm. Haiti had pleaded for emergency international aid after the late-summer conga line of storms laid waste to parts of Hispaniola, the island Haiti shares with the Dominican