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: - Dr Suzy Moat, from Warwick University's Business School, is testing new technologies to monitor crowds - Dr Cliff Stott, a psychologist from Leeds University, says the answer lies in better crowd management - Paul Townsend, Associate Director of 'Crowd Dynamics International', would like more focus on how we design and use public spaces 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.