Sounds like bud blast - something happens to make nice buds go bad and they either fall off or freeze. Most often from too much fertilizer or too much water. This may not be the case if your other lilies nearby are fine. Maybe you can play detective about if a low spot collected water or if these bulbs were near the lawn and get hit with high nitrogen plant food. Perhaps the roots were damaged by a vole or mole. Poke around the root zone a bit. Otherwise, keep waiting and if the buds never open and begin to rot cut them off and leave the foliage to turn yellow and supply nutrients for next year's flower display. Keep growing, Marianne Binetti