A massive fish kill along a 40-mile stretch of the Ogeechee River is puzzling environmentalists, who have closed public landings and are awaiting test results to learn the cause. Georgia Department of Natural Resources Environmental Protection Division spokesman Keith Chambers said public landings were closed Sunday in Screven and Bulloch counties, and said the fish kill is possibly affecting Bryan, Effingham and Chatham counties as well. Monday, authorities investigated King America Finishing, a fabric-finishing plant in Dover, about 15 miles from Sylvania in Screven County that is located on the river.