An arsonist, who was never caught, set fire to the church on May 2, 1873. Damage was limited to the altar. A new altar was installed later that year with a painting of St. Margaret that now hangs in the present cathedral. Another criminal act affected the parish in the early hours of the morning of March 31, 1878, when two gunmen and a third individual attempted to rob the parish of a collection from the Forty Hours' Devotion the night before. One of the gunman shot at, but missed, Father Cosgrove who was still in bed. They escaped without the collection, but with jewelry from the housekeeper's daughter. A $3,000 reward was offered and the three men were caught and sentenced to prison terms at the Anamosa State Penitentiary.