Complex sentence: The MacArthur Causeway connecting Miami and Miami Beach was submerged under of water, and communication between the two locales as well as the rest of the United States was cut after all local telecommunications and power lines were blown down.
Split into simpler sentences: The MacArthur Causeway connecting Miami and Miami Beach was submerged under of water. Communication between the two locales as well as the rest of the United States was cut after all local telecommunications and power lines were blown down.