Well, we missed this bit of excitement - https://www.derbytelegraph.co.uk/burton/live-sainsburys-evacuated-after-reports-2950723? - Sainsbury's is just across the road from the exhibition venue.
The cops said - "At 5.30pm we were called to reports of a piece of unexploded ordinance in Robian Way, Swadlincote.
What was believed to be a small World War 2 bomb had been found by a member of the public and a 100 metre cordon was put in place.
This resulted in a number of premises being evacuated as a precaution.
After consulting the Explosive Ordinance Division from Chetwynd Barracks, Chilwell, the device was found not to be live.
The cordon was lifted at 8.20pm and all premises were re-opened to the public.
We would like to pass our thanks to members of the public for the patience whilst this situation was resolved."
From that statement, the venue would have been outside the cordon, the discovery was about 200 metres away.