In 2021, Champlain Towers South – an apartment building near Miami – collapsed, killing 98 people. This film forensically examines what happened and asks: what went wrong? And could more buildings across the world be at risk of a similarly catastrophic fate? On 24 June 2021, Champlain Towers South – a 13-storey residential building in Surfside, Florida – collapsed in just 12 seconds. Fifty-five apartments were reduced to rubble, and 98 people lost their lives. What might have caused one of the worst building failures in modern history? There is still no official explanation. This programme examines what went wrong and investigates the implications for other buildings around the world, including those in the UK. Emotional eyewitness testimony, tense bodycam footage from first responders, news archive footage and 3D CGI animations are used to piece together the definitive, moment-by-moment account of this disaster.