A 5-year-old girl is brought to the ENT clinic 3 days after her parents noticed she was coughing intermittently and had a low-grade fever (38.2°C). She had been playing with small toy beads the previous week. On examination, she is afebrile now, with mild bilateral wheezing on auscultation. Anteroposterior and lateral neck X-rays are normal. Chest X-ray shows patchy consolidation in the right lower lobe. Flexible bronchoscopy reveals a small plastic bead lodged in the right lower lobe bronchus with surrounding mucosal edema and purulent secretions. What is the most likely complication that has already occurred?