There's no ammunition on it. They empty the ship of weapons/aircraft during maintenance cycles. Some equipment they locked in a Marine cargo hold during the maintenance caught fire. Probably lithium battery related to hot weather and the environmental controls shutoff.
Ok than its good, i think this is one con of having such large ship, as the news anchor said fire could burn for days, it would difficult to fight it , now i never see inside of a AC but from the movies ,it seems they have many narrow corridors or passages which would be hard to access for fire fighters .