Dozens gather in London to mark one year since a cataclysmic explosion ravaged Beirut, Lebanon, becoming the country's worst peacetime disaster at a time when its economy was already in tatters. In remembrance, London's Lebanese community and supporters sing the Lebanese national anthem, organize speeches and express frustration over efforts by political leadership to stall a formal investigation into the blast. "Someone needs to take responsibility of what happened and up until now, we don't have that responsibility," says 29-year-old Ahmad Dimassi. IMAGES AND SOUNDBITES