Parents won't eat their frys.
Other fishes in the tank would. if you want parents raise the fry, remove other fishes out.
of coarse they will, just because they are from the cichlid family and they are supposed to guard their fry does not mean they will every time. i had an old pair that i put in a separate tank to breed and they still ate their eggs, like achill3s said, usually its stress, either by other fish, or sometimes by outside traffic around they tank. they need to feel safe, thats why having the tank with plenty of hiding spots and some even cover the sides and back to get them to have a successful batch.
but back to the center of this thread, its not that the parents are eating his fry, its that they are not fanning them with oxygen enough for them to survive. in which case, raising them artificially would definitley be worth a try