Amphibious?excavators?escorted?by?armed?policemen?have?roared?through?Makoko,?Africa's?largest?and?most?legendary?floating?slum?in?recent?days,?crushing?hundreds?of?wooden?shacks?built?on?stilts?above?the?lagoon?in?the?heart?of?Lagos. The?operation?is?the?latest?of?a?campaign?to?remove?what?authorities?in?Nigeria's?commercial?capital?describe?as?illegal?structures?and,?critics?say,?reclaim?waterfront?land?for?real-estate?development. Three?people,?two?of?them?babies,?have?died?from?effects?of?teargas?fired?by?police?since?the?clearances?began?two?days?before?Christmas,?three?rights?groups?said. ?...