An 11-month-old boy presented to the emergency department with a 24-hour history of barking cough and sudden onset of increased work of breathing. The family reported that his respiratory difficulty acutely worsened after a bout of forceful coughing shortly prior to arrival. On examination, the patient was ill appearing. His vital signs revealed a respiratory rate of 50 breaths/min and oxygen saturation of 76% on room air. The patient was in moderate respiratory distress, with grunting and retractions noted. There was no stridor. Auscultation of the chest revealed decreased breath sounds on the left. A portable chest radiograph was obtained (Figure 1).