Here is a link to Lowell Knuth in the 1940 census.Interesting Lowella is listed as a widow and there are 3 other adult females in the house, called "partners".They are all affiliated with the Salvation Army. You may have to cut and paste this link into your browser.
In Fargo there was a Florence Crittendon home where unmarried (& other status) women could go and have their babies, receive training and stay at the home--sometimes for a couple of months.The Crittendon home has been closed for many years.North Dakota is fairly strict regarding adoption regulations & contact usually requires cooperation from the adoption agency or a court order to open the records. Spendy! Sometimes you can get non-identifying information from the agency and be able to figure it out.
Catholic Family Services, Lutheran Social Services could be the 2 logical choices--but I wonder if the Salvation Army might have a division for that as well.Years ago the S.A. used to have a service to find missing folks if a family had misplaced a member.There is a database that contains a few cases of legal name changes of Cass County (Fargo's county) that is searchable online and could represent some adoption type records.
The fire you mention was the burning of the state capital building and occured in 1930 and NO vital records were lost as a result.