Sorry to hear that. They won't die from being overfed directly. Fry are supposed to eat more to grow. They'd suffer if the overfeeding is causing mini ammonia spikes as the filtration may not cope depending on tank setup.
But one fry out of the bunch just happens. It could have had birth defect, just like humans.
But one fry out of the bunch just happens. It could have had birth defect, just like humans.