2014 Sydney hostage crisis
After the siege began, a staged exclusion zone was established with thousands of people evacuated from nearby buildings, including from the floors above the café. The Sydney Opera House was evacuated after a suspicious package was found; however, reports were unconfirmed by police. The US Consulate General in Sydney, located in Martin Place, was also evacuated. Some Sydney schools were put in "white level lockout" due to the hostage situation, which meant that no school group was permitted to leave the school grounds.
M24 Japanese Midget Submarine wreck site
As at 18 October 2012, the M24 was of heritage significance to Australia and Japan and is the only Japanese midget submarine wreck located in Australian waters (the remains of two others from the Sydney attack being recovered). The site is the only in situ identified cultural relic surviving of the attack on Sydney Harbour in 1942. A complacent Sydney population awoke to the realisties of war and the event is strongly remembered today through the wider community. The M24 wreck is representative of Japanese submarine operations off Australia's eastern seaboard during the war and a direct physical reminder of the conflict at Sydney. Internationally, it represents one of only a handful of Japanese midget submarine wreck sites located in their unique underwater contexts. Remains of a further six are retained as static museum or outdoor display exhibits. The archaeological site is therefore of considerable importance in the comparative analysis of midget submarines wrecks discovered worldwide. The site also has the ability to contribute generally to studies of submarines as a specialised class of archaeological site type. Only limited archival information related to these vessels survives and therefore the archaeological record is of added importance. In regard to the three submarines that attacked Sydney Harbour, M24 is the only one retained in its original battle context and undisturbed, apart from the obvious effects of net entrapment and corrosion activity.