Otto Lloyd Iverson

We are trying to find out what happened to a relative, Otto Lloyd Iverson, born in 1922 in Beulah, Mercer County, ND. His parents were Christian Matthew Iverson (1880-1968) and Alida Helland Iverson (1887-1935). Otto's sister, Anna Belle Easton, had apparently arranged for her brother to live in a retirement or nursing home in Milwaukee, WI. When Anna died in ND Oct. 7, 2002, neighbors tried to contact the brother, but the letter was returned unopened. Does anyone have access to death records in and around Milwaukee? We have tried to get help from the Deeds Office at the Milwaukee County Courthouse, but they will not help us unless we know the date of his death (vicious circle...). Thanks for any information!