MOUNT VERNON, Wash. (AP) — Days of torrential rain in Washington state have caused historic floods that have stranded families on rooftops, washed over bridges, and ripped at least two homes from their foundations. Experts have warned that even more flooding expected Friday could be catastrophic.

Washington is under a state of emergency, with evacuation orders affecting tens of thousands of residents. Governor Bob Ferguson urged everyone to follow evacuation instructions as yet another river nears record levels. About 78,000 residents of a major agricultural region north of Seattle were ordered to leave their homes as the Skagit River was expected to crest Friday morning.

The floods impacted large areas, with many major roads washed out and some without alternate routes. Photos revealed scenes of devastation, with landslides blocking transportation routes and homes surrounded by rising waters.

Authorities reported that helicopters rescued families stranded in Sumas, where floodwaters reached 15 feet (4.6 meters), and rapid response efforts continued across the state as another storm system looms, promising additional rainfall and potential further flooding.