Everything can be fixed.
Some repairs can be done through the f-holes. If the bass has been opened for repair I check the stability of the inside before I close it. An open bass is also a good opportunity to talk about the possibilities of sound improvement.
If your bass gets damaged I would advise you to carefully collect the pieces that broke off. In many cases it is wise to lower the tension of the strings to prevent further damage.
Cracks are mostly caused by impact damage and by air humidity. The best air humidity for double basses is between 40% to 50%. You can measure this with a hygrometer.
There are some risk factors to keep in mind like frost, temperature changes, sun, heaters, hot stage lamps and the heater/airco in your car.
When the outside temperature drops below zero Celsius, I would advise you to use a dampit and put a bowl with water on the heater and. Use your case to protect your double bass from changes in temperature and low humidity.
We are open to discussion if you would like to trade in a broken bass.