Following the death of three reservists, Adam Fleming investigates whether deaths and injuries like these can be avoided. Three members of the Territorial Army have died after attempting a special forces selection course in the Brecon Beacons on one of the hottest days of the year.

People who have gone through the process in the Welsh mountains believe that the new recruits were marching from point to point, carrying heavy rucksacks in a gruelling test of their fitness and navigation skills. They would have been carrying water, emergency flares and GPS tracking devices.

The Police, the military, the Health and Safety Executive and the local coroner are investigating but events are still shrouded in mystery. In this edition Adam Fleming asks what precautions would have been in place and investigates the safety of military training.