A SERGEANT has died after being injured in a live firing exercise. It is understood the incident occurred at Castlemartin Training Area in Pembrokeshire and led to the death of Sgt Gavin Hillier. An Army spokesperson said: “It is with great sadness we can confirm the death of a soldier on March 4. “Our thoughts are with his family and friends at this tragic time. “The circumstances surrounding this death are being investigated and it would be inappropriate to comment any further.” In a post on social media, his father wrote: "Absolutely devastated to be writing this post, probably the hardest thing I’ve ever had to do.