50cm wide hole, 20cm deep on the edge of the road

The tree was removed as it was damaged years ago and the remaining stump has now disintegrated causing a huge hole. The kerbside is dropping further into the road which is located close to a drainage grate. I have witnessed several near misses with adults and children walking along the pavement especially when dark, as it's difficult to see the hole. I have also witnessed damage to cars who have parked/stopped outside and not seen the hole.