Answer:
They will be unable to breathe and may die of asphyxia if not medicated.
Step-by-step explanation:
When the diaphragm muscle contracts, the thoracic cavity expands and this creates an area of low pressure compared to the outside environment. This allows air to rush in through the nose into the lungs. When the muscle contracts, the converse occurs. The thoracic cavity contracts creating an area of relatively high pressure. The air in the lungs is pushed out.
Therefore if the muscle is affected, breathing will be difficult leading to asphyxiation.