Most of the posts above rightly focus on the circumstances of the accident. But step back for a moment and let the numbers speak about risk. Most of the people attending air displays will have flown only as airline pax where the fatal accident rate (2002-2011) is about 0.04 fatal accidents per 100,000 flying hours. Some will have knowledge of general aviation where the AAIB report that the rate is 1.3 fatal accidents per 100,000 flying hours.
This AAIB Report suggests that there was one fatal accident per 2960 air display items in the period 2008-2015, but hasn't the courage to calculate the accident rate. Assuming each display item was 15 minutes (change the numbers if you like) that translates to 135 fatal accidents per 100,000 hours flown.
I doubt very much that Joe Public and his wife and children attending a display have any inkling of these relative levels of risk i.e. 3375 times higher than experienced on a commercial flight. Perhaps they should be told.