The seedlings may or may not emerge from the soil. The type of injury observed is emerged seedlings with the leaves not unrolling properly. The leaves seal together and the new tissue continues to emerge and tries to push itself out. The result is seedling with the tip of the leaves sealed and bent to the side and the lower part of the leaf loops upward. It is quite a distinctive symptom.
Nothing can correct the problem once it occurs.
If the corn emerges and this symptom is seen, the corn often grows out of the problem, although the first few leaves maybe torn. Under severe conditions, or in situations where the corn does not emerge, stand loss can occur and re-planting considerations come into play. If corn is having difficulty emerging, a light rotary hoeing can loosen the crust and assist the plants in emerging. I have seen severely injured seedlings produce a normal looking mature plant. Decisions must be made on a field by field observation.