Massive fire engulfs Notre Dame Cathedral in Paris
Firefighters in Paris relentlessly fought the flames that engulfed the Notre Dame Cathedral on Monday. The fire chief said they managed to save the main structure of the cathedral, but there remains a concern that interior structures will collapse. Adam Thiel, fire commissioner for the Philadelphia Fire Department, joins CBSN to explain why the flames might have been difficult to extinguish and how the cathedral's old age could have played a role.