ELEUTHERA, Bahamas — Hurricane Joaquin unleashed heavy flooding as it roared through sparsely populated islands in the eastern Bahamas on Thursday as a Category 4 storm, with forecasters warning it could grow even stronger before carving a path that would take it near the U.S. East Coast. The storm battered trees and buildings as surging waters reached the windows of some homes on Long Island in the Bahamas and completely inundated the airport runway at Ragged Island. There were no immediate reports of casualties, according to Capt. Stephen Russell, the director of the Bahamas National Emergency Management Agency.