I have a composite marble (walk-in) shower with a 10" crack on the floor of the pan 1/2 way between the drain & door. Is there a way to repair this of am I looking at a COMPLETE demolition and replacement of my shower? The home is only 3 years old but as luck would have it, the warranty is only for 2 years so now I own both sides of the crack and any potential water damage. All thoughts and ideas are welcome! Thanks!

You can try to patch it with a 2 part epoxy glue but it may not look very good. The crack is due to poor installation and support under the pan, it now has a slight flex to it and complete tear out is likely needed for a great looking fix