If they had lived out their lives as they should have, the children killed in one US city would have 818 years between them. Years to have relationships, careers, mistakes and successes.

Since April 2019, 13 children have been killed by gun violence in the city of St Louis, Missouri. The oldest among them were just 16, the youngest was Kayden Johnson, a two-year-old baby.

In St Louis, the life expectancy of the average adult is 74.1 years (based on data from 2008 to 2016 published by Missouri’s department of health). If you assume that these children reached that average life expectancy had they not been killed by guns, they would have together had an extra 818 years between them. But averages are more complicated than that. In a city as deprived of resources as St Louis, even your zip code matters – in some parts of the city, the life expectancy is as low as 69 years.

If those children had been born outside of St Louis, they could have expected longer lives. Nationally, the life expectancy of people born today in the US is 78.6 years. But none of these children were white – a fact which also cuts short the lives of millions of people in the US. Black children born today are expected to live almost four years less than their white peers.