HOT SPRINGS, Virginia — Where the tidy brick sidewalks end at the edge of the business district, the carnage was jarring. Two cars had their roofs sheared off. Shattered glass was strewn everywhere. In the distance, an older van was upturned, on its roof, alongside two vehicles on their sides and another car in a ditch, completely upside down and touching the creek.

Known colloquially as Sam Snead Highway, the winding road that hugs the Allegheny Mountains and serves as the thoroughfare for this charming town is still damp from a violent evening downpour. The initial assumption is that all six vehicles met this gruesome fate after hydroplaning on the single-lane highway.