Christchurch 1996 Quake Doco - why buildings collapse

Go to: https://www.youtube.com/watch?v=lnarVAoiZ7A to view 2016 quake doco! At 8.30pm on 11th July 1996 an 'Inside New Zealand' documentary was transmitted on TV3 called; 'Earthquakes!' Part of it reviewed Christchurch's quake readiness and shows that many of its current building problems were foreseen, including a possible explanation as to why some buildings collapsed catastrophically. Go to: https://www.youtube.com/watch?v=lnarVAoiZ7A to view 2016 quake doco!