The answer to 'why is my bathtub burst pipe' is a burst pipe in the bathtub is typically caused by a buildup of pressure, freezing temperatures, or a physical break in the pipe. Symptoms may include water leaking from the tub, low water pressure, or visible damage to the pipe. Solutions can range from simple DIY fixes to calling a professional plumber, depending on the severity of the issue.
If the burst pipe is relatively small and accessible, you may be able to repair it yourself by turning off the water supply, removing the damaged section of pipe, and replacing it with a new section. However, if the pipe is located behind walls or the damage is more extensive, it's best to call a licensed plumber who can properly diagnose and fix the problem.