After Pacific Ocean Park closed it´s doors forever in late 1967 the era of the so called "Coney Island if the Pacific" came to a sad end.
Due to urban re-development the area around the pier became a seedy place. With the closing of P.O.P, the decay of the neighbouring area called Dogtown got worse.
All sellable assets of P.O.P were auctioned off (parts of the Hawaiian tiki decoration of the "Mystery Island Banana Train Ride" later turned up in one of Germany´s first theme parks). Since some rides were too old and too heavy, they were left to rot on the pier. So the massive "Mahi Mahi"-Tower, which had served as an impressive backdrop for the showdown of "The Fugitive" a few months earlier became an eerie landmark of the abandoned funland.
The dilapidated pier was not only dangerous because of the crumbling wood, it was also a hide-away for several outcasts. Among them were the surfers of Dogtown who would later move to the empty canals and swimming pools of Venice Beach to famously swap their surfboards for skateboards.
As far as I know, Hollywood had also lost its interest in P.O.P. Only a 1972 French/American co-production used the ruins of the pier for an effective showdown: Une homme est mort (aka "The Outside Man") featured Jean Louis Trintignant as a French contract killer who is lost in L.A while trying to do his job. Sadly the movie, which also features Anne Margret, Angie Dickinson and Roy Scheider, is not available on DVD. As mentioned before, the quiet showdown in the sun drenched ruins of the amusement pier us very haunting.
Finally the city of Venice decided to get rid of the "eyesore" and by 1975 all traces of the pier had disappeared. Since debris and stilts are still lying in the water, it is still forbidden to swim and surf where the pier once stood.
Check these great sites about P.O.P: Rest in Peace - Pacific Ocean Park and The underground website of P.O.P..
Part 1&2 of my P.O.P-trilogy here and here