Hi, Vesa--looks like most of the family stayed in Cascade County. I found death records for three of them. You might try posting a request for obituaries on the Cascade County genweb site and see whether someone will look them up for you. That will tell you the names of survivors and where they live.
Hulda Kukkola died Jan. 14, 1977, Cascade County
Eugene R. Kukkola died Sept. 5, 1988, also in Cascade County
Albi Kukkola Kencke died Dec. 26, 1997, Cascade County