DARRINGTON, Wash. — Estimated financial losses from the deadly Washington mudslide that has killed at least 24 people have reached $10 million, Gov. Jay Inslee said Monday in a letter asking the federal government for a major disaster declaration.

In seeking additional federal help following one of the deadliest landslides in U.S. history, Inslee said about 30 families need assistance with housing, along with personal and household goods. The estimated losses include nearly $7 million in structures and more than $3 million in their contents, Inslee’s letter said.