A 3-year-old boy is rushed to the emergency room in acute distress. The child has vague chest pain and difficulty swallowing. He refuses to drink water. Physical examination shows drooling and salivation. Vital signs are normal. The mother states that she saw the boy ingesting a liquid used to clear drains. If this chemical was a strong acid, which of the following histopathologic findings would be expected in the esophagus of this child?