Complex sentence: After passing by the Kensico Reservoir in Valhalla, the tornado crossed into Connecticut, where it knocked down numerous power lines, cutting power to about 10,000 residences in the county.
Split into simpler sentences: After passing by the Kensico Reservoir in Valhalla, the tornado crossed into Connecticut. The tornado knocked down numerous power lines, cutting power to about 10,000 residences in the county.