Fractured wrist

[CYNthesys]

My 66 yr old sister who lives in London fell and fractured her wrist in September whilst walking on pavement. It wasn’t a normal case of raised paving stones etc.Where she lives there is a problem with cars usually parked on the pavement which leaves very little room left for pedestrians to use pavement. My sister is also awaiting cataract surgery, so it makes it even more difficult for her to navigate the narrow pavement space that is left. She wrote and advised the council of her fall and injury and pointed out that the council had failed in its duty of care by failing to enforce the parking regulations. The council hasnt even bothered to acknowledge her letter.Need advice on next steps please