It's the flower stalk. It has never happened before. What can I do
Unfortunately, your photos did not come through. I am unable to see the damage.
I would be sure to keep the soil moisture, as they prefer bog like conditions. Otherwise it could be due to disease.
This article will help you to know what care they require:
https://www.gardeningknowhow.com/ornamental/bulbs/crinum-lily/crinum-lilies.htm
These articles will help you to test your soil:
https://www.gardeningknowhow.com/garden-how-to/soil-fertilizers/testing-moisture-in-plants.htm
https://www.gardeningknowhow.com/garden-how-to/soil-fertilizers/testing-soil.htm
https://www.gardeningknowhow.com/garden-how-to/soil-fertilizers/soil-ph-plants.htm
https://www.gardeningknowhow.com/garden-how-to/soil-fertilizers/test-soil-for-pests-and-diseases.htm
I have grown milk and wine crinum lilies for years in the same area of our garden with great success. This year, most of the bloom stalks are curvy from the base emerging from the bulb, and are much shorter than usual. However there are others that appear normal—tall and straight. We had a late hard freeze this year. Could that be the cause or perhaps over-crowding? There are no signs of disease. I attached 2 photos, but I am not sure I was successful. They do not appear in this questionnaire.
That type of occurrence is usually weather related or an environmental upset such as herbicide drift. The freeze may have caused it as you suggested. I expect it will return to normal next year. I didn't find that was a sign of overcrowding, and unless you think yours are really crowded, crinum lilies resent having their roots disturbed. Here is some info that may help:
https://plants.ces.ncsu.edu/plants/crinum-americanum/
https://www.gardeningknowhow.com/ornamental/bulbs/crinum-lily/crinum-lilies.htm