The answer to 'why is my drain burst pipe' is that a burst pipe in the drain is typically caused by a blockage, freeze damage, or excessive water pressure. Symptoms include water backing up, slow draining, and visible cracks or leaks in the pipe. Solutions may involve clearing the blockage, repairing the damaged pipe, or adjusting the water pressure.
If the burst pipe is in an accessible location, you may be able to fix it yourself with basic plumbing tools and materials. However, for more complex issues or pipes located in walls or underground, it's best to call a professional plumber who can properly diagnose and repair the problem.