Haiti on Wednesday marked the first anniversary of its devastating earthquake, with the country still struggling to recover in the face of political instability and other problems.Schools and government offices closed for a national day of mourning as Haitians gathered at observances, including a Catholic Mass at the quake-destroyed remains of the National Cathedral in the capital, Port-au-Prince. More than 200,000 people were killed in the earthquake, while 1 million others were left homeless.One year later, conditions in Haiti remain difficult. Hundreds of thousands of displaced people are still living in camps. Rebuilding work has barely begun despite billions of dollars in pledged aid.Political uncertainty looms as the country awaits a presidential runoff election, and a cholera epidemic has killed more than 3,600 people.Former U.S. President Bill Clinton, the United Nations' special envoy to Haiti and co-chair of a recovery aid campaign, is in Haiti to take part in the commemorations.