the 1965 palm sunday tornado outbreak was the second tornado outbreak to strike the united states on palm sunday. from april 11 to 12, 1965, tornadoes touched down in iowa, illinois, indiana, wisconsin, and michigan. it was the second biggest outbreak at the time. 271 people were killed, and 1,500 injured and it is the deadliest tornado outbreak in indiana's history, with 137 people killed in that state.