The worst flooding to hit Hawaii in two decades swept homes off their foundations, floated cars out of driveways and left floors, walls and counters covered in thick, reddish volcanic mud. Crews continued to assess the destruction Monday, but new downpours set off a fresh round of flooding on Oahu’s south side even as residents on the island’s North Shore cleaned up and assessed the destruction from last week's deluge. Authorities said hundreds of homes were damaged, along with some schools and a hospital. No deaths have been reported, but more than 230 people had to be rescued. Gov. Josh Green said the cost of the storm could top $1 billion.