This 38 year old woman presented at her local accident and emergency department complaining of severe pain on the right side of her chest. The pain started earlier in the day after she had a dizzy spell and fell, hitting a piece of furniture on the way down. The pain was worse on inspiration and on movement. On examination the lower, anterior ribs on the right were tender to palpation, she was in obvious distress, and the nurse reported that her respiratory rate was18, with a SpO2 of 95% on room air. An x ray examination was taken of her chest and the result is shown here.