Destructive flooding in the Pacific Northwest has caused a highway to crumble and collapse into the river below. But what exactly caused the detrimental downpour? Meteorologist Stefano DiPietro explains. | WSMV 4, Nashville

An atmospheric river event has caused catastrophic, record-breaking floods across Washington state. This video shows dramatic footage of overflowing rivers, inundated towns, and emergency crews conducting daring rescues as communities face a state of emergency. | The Weather Network