THE STANDARD The road and rail then moved from the bridge to the causeway, effectively shutting the waters to their respective sides, and closing the island chapter altogether. [Courtesy] Before that, an 1899 Salisbury bridge stood over the waters, maintaining the island's integrity and allowing waters and marine life of Makupa straits to flow freely. But the vagaries of the first world war, specifically the fear of aerial attack on the bridge drove the British to fill the causeway to guarantee communication of the island with the mainland. The road and rail then moved from the bridge to the causeway, effectively shutting the waters to their respective sides, and closing the island chapter altogether. Mombasa ceased to be an island in 1929 when Makupa Causeway was launched.