Ouch, that hurts.

It looks like someone has tried to reglue the bridge!

Maybe try something similar to how you mend a hole in plasterboard!!
Straight up, and (disclaimer) I have never done this - I think I would remove the bridge completely using a chisel. Clean up the body with a chisel. Clean the bottom of bridge. Remove the damaged section of top (which is smaller than the size of the bridge). Add/glue a solid piece of wood/ply (bigger than the "hole") under the damaged section and well under the strong undamaged section. Add/glue a ply piece to fill in the damaged "hole". Sand the new top flat. Reglue the bridge.

Sounds easy

Good luck. I will think some more on this as well. I would also look online for other suggestions.
Definitely proceed with caution!