In August 1977, Father Willmann was in the United States for the Ninety-Fifty Annual Supreme Council Convention.   That year, it was scheduled from August 14^th to the 17^th, at Indianapolis, Indiana.  The Philippine delegation then was composed of Father Willmann as its head, and the two other members: Bro. Nicanor Y. Fuentes and Bro Concelio B. Cagurangan.

After the Convention, Father Willmann proceeded to New York, presumably to visit his sister Ruth, a Franciscan nun residing at Roslyn.  Prone to falls because of his fragile limbs, the 80 years old Father, unfortunately, had a fall while he was in New York, which required a hip-bone surgery.  He was confined initially at St. Francis Hospital in Roslyn, then transferred to Murray-Weigel Hall in New York Province, an infirmary probably belonging to the Jesus, on September 8, 1997.  When he was discharged from the hospital to recuperate at the Jesuit House at Fordham, everyone thought that Father Willmann was already out of danger.  On September 14, 1977, much to the distress of those who had anxiously anticipated his recovery, Father Willmann succumbed to a cardiac arrest.