Simplify the following text for a Grade 8 native English-speaking person.
Original: The doubling up of walls and ceilings was a special way of stoppng the walls from collapsing if the fort suffered a direct hit from a missile ( rocket ) fired from an enemy ship .
Simplified: The doubling up of walls and ceilings was a preventative measure meant to stop the walls from collapsing in the event of a direct hit .