On this answer to this question regarding the merits of angled flightdecks on aircraft carriers, @JanHudec makes this interesting observation:
You don't really have "two flight decks". The catapults are well distributed, but there is just one set of arresting wires, so while hit to the bow disabling catapults 1 and 2 would leave 3 and 4 available, hit to the landing area still prevents all landings. [Emphasis added.]
Why don't aircraft carriers have multiple redundant sets of arresting gear, to allow them to land aircraft even if one of the landing runways is disabled by battle damage?