Andy Murray called the mass shooting at Robb Elementary School “unbelievably upsetting”. The Wimbledon champion and survivor of the UK’s deadliest mass shooting – the 1996 Dunblane massacre when he was nine-years-old – revealed that an 18-year-old gun man opening fire and killing 19 children and 2 teachers at a school in the city of Uvalde in Texas with an AR-15 made him “angry”. Of the second deadliest school mass shooting in US history, the 35-year-old tennis player told BBC Sports: “It’s unbelievably upsetting and it makes you angry. I think there’s been over 200 mass shootings in America t…