It is helpful when posting a query to list all information you have already collected on an individual.
I see by your family tree that you have found Adam in Omaha city directory entries for many years, You also have a couple of census records, but should be able to find the family in others.
Is your main search for a death date and place for Adam?
Omaha World Herald
Omaha, Nebraska, Thursday, November 10, 1921
FORMER SOUTH SIDE MAN DIES SUDDENLY
Adam Henry Kerst, 60, a former resident of the South Side, died suddenly Tuesday at the home of his son, Carl, 4963 North Nineteenth street. Besides his son he leaves a daughter, Mrs. Ray Benolken. The body was taken to Korisko's pending funeral arrangements.