A vehicle ended up in a sinkhole following a water main break near 12th Street and Hildreth Street in Davenport on Tuesday morning. According to city officials, the water main break caused the ground beneath the roadway to become unstable, creating a sinkhole that swallowed part of a vehicle. The damaged water main also left approximately 75 customer connections without water for much of the day while repair crews worked to restore service. In this case, the sinkhole was caused by a water main break, not by natural underground caves. Here's how it happens:A water main breaks beneath the road.