https://chroniclingamerica.loc.gov/lccn/sn83045211/1918-05-30/ed-1/seq-1/#date1=1918&sort=date&date2=1918&words=Influenza&language=&sequence=0&lccn=&index=17&state=&rows=20&ortext=&proxtext=influenza&year=&phrasetext=&andtext=&proxValue=&dateFilterType=yearRange&page=19

The influenza epidemic in Spain is being blamed on the crews of interned German U-boats. The disease is said to be effecting horses. At Memorial Day events Senator Phelan (CA) challenges the Irish Fenians to fight the Germans first, and the Veterans of the Grand Army marched. All but six of the Philadelphia Rapid Transit Company motormen and conductors return to work after a strike.

Source: "Blame U-Boats for Epidemic," Evening Public Ledger, Philadelphia, Pennsylvania, May 30, 1918. Page 1, Column 2.