A deadly crowd collapse at the Hajj pilgrimage in September has brought public safety into the spotlight once again. Here in the UK, the Hillsborough inquest has been re-examining the tragic events of 1989 which led to the death of 96 football fans at the Sheffield ground.
Today we ask how science can prevent crowd disasters. Jim Al-Khalili invites three scientists into the studio to explain their strategy for improving crowd safety:
The panel debates the pros and cons of each method and how we can put science to work to keep crowds safe.
Producer: Michelle Martin.