 Cagney, in an uncharacteristic move, decided to forgo a stunt double and play the scene himself in which his character is struck by a whirling propeller.At first things proceeded smoothly, but when it came time for him to fall into the lake, he overdid it and suffered a real concussion, putting the 10-day shoot at North Bay, Ontario farther behind schedule.Weather was a constant challenge, and with the need to ensure continuity, small scenes became unnecessarily complex; as a result, a typical shooting day lasted almost into the night.