It's a very special day for one of Australia's most recognised landmarks. 90 years ago today, the Sydney Harbour Bridge officially opened to the public. Since then, it's become a well recognised symbol of Australia around the world. But to the residents of Sydney, it's so much more than a tourist attraction. And when things go wrong, it causes chaos across the whole metropolitan area. Tonight, 7NEWS presents the ‘Sydney Harbour Bridge 90th Birthday’ special - a look back at the history of the Sy