James Cagney was originally supposed to play Nick, but when The Public Enemy (1931) became a big hit, it was decided that he should no longer be relegated to supporting roles, allowing the relatively unknown Clark Gable to step in instead.
In an earlier draft of the script, intern Eagan planted the skeleton in a baby carriage, not Lora's bed. The startled Laura dropped the baby she was holding, with tragic results. Eagan admitted to his guilt and was fired from the hospital. However, the sequence was changed to the one which is now appears in the film.