A newly finished brick wall mostly obscures from the view of leaders arriving at the Summit of the Americas a slum that embodies their biggest challenges: drug-related violence and an economic crisis that threatens to erase gains against poverty.The people of Beetham Estate, which flanks the main highway entering Port of Spain from the east, call it "the wall of shame," though community activist Sherma Wilson says it was built to shield them from the highway, not vice versa.Beetham is home to some 5,000 people, about a tenth of them squatters. A block-wide slice of simple dwellings that runs most of a mile and is wedged between motorways, it is a place outsiders shun for the danger.A coconut-processing plant spews milky waste into a scum-coated pond that intersects the neighborhood, emptying into a malodorous mangrove swamp. After heavy rains, crud overflows into many of the one-story brick and mortar homes.