Oso, Was. (CNN) — At least three people are dead, and several others hurt or missing after a landslide Saturday, about an hour outside of Seattle, Washington.

It happened on State Road 530. Crews have been working for nearly 24 hours trying to find people trapped under debris.

A fire department captain for the city of Arlington said they could hear cries for help.

There are also concerns about a potentially “catastrophic flood event” because a river is now blocked.

Groundwater saturation tied to heavy rainfall in the area over the past month is being blamed for the landslide, which authorities say is at least 45 yards wide.