What causes closed homes and barns to explode during a tornado?

The correct answer highlights that the difference in pressure within the tornado's vortex is the primary cause for closed homes and barns to explode during a tornado. When a tornado forms, it creates a powerful vortex with extremely low pressure at its core. If buildings have tightly sealed windows and doors, the air pressure inside the structure can remain much higher than the pressure outside, especially as the tornado approaches and its wind speeds increase.

As the tornado passes over, the rapid drop in external pressure can create a significant pressure differential. This difference can be strong enough to cause the walls, roof, and other structural components of the building to fail, sometimes resulting in explosive decompression. Essentially, it’s this disparity in internal and external pressure that leads to the destructive effects observed in structures caught in a tornado's path, rather than factors such as wind speed or moisture content.