Emergency services in Brighton were put to the test today. An explosion was staged at a disused army barracks to see how police, fire and ambulance crews would respond.
Around 200 volunteers took part with other incidents staged across Sussex.
Andy Dickenson reports and speaks to Insp Tony Lumb from Sussex Police and Mark Rist from East Sussex fire and Rescue.
More top news
Sunny spells continuing to develop into this evening. Dry with mostly clear skies overnight, before a sunny but chilly start tomorrow
Dry with sunny spells into this evening. Turning chilly with clear spells overnight with a sunny but cold start tomorrow
Dry with an increasing amount of bright spells this afternoon but feeling cool