An investigation is under way after a fire damaged a well-used pier. The walkway off Mark Lane, in Denton near Gravesend, partially collapsed on Saturday (August 31) and has been taped off. Pictures of the wooden structure, which is near the Ship and Lobster pub, show the extent of the damage. Part of the walkway has collapsed into the River Thames below with fragments scattered along the shore. The entrance has been taped off to stop visitors using it. A spokesperson for the City of London Corporation, which acts as the London Port Health Authority for the tidal Thames and is responsible for …