Chest X-ray of a 40-year-old male coronavirus disease 2019 (COVID-19) patient. Right pneumothorax of 30 mm. “Deep sulcus sign” was noted (black arrow). This patient developed pneumothorax after a cycle of non-invasive ventilation with a helmet interface. Ventilation was set at pressure support, 8 cm H2O; positive end-expiratory pressure, 10 cm H2O; and fraction of inspired oxygen, 0.55.