Complex sentence: Swarms of tornadoes began touching down after 5:00pm, in the northwest part of that state, some of the hardest hit were towns such as Atlantic, Albion, Bradford, and Cooperstown.
Split into simpler sentences: Swarms of tornadoes began touching down after 5:00 pm in the northwest part of that state. Some of the hardest hit were towns such as Atlantic, Albion, Bradford, and Cooperstown.