Brecon Beacons soldiers deaths: Emergency response caught on camera
15 July 2013 Last updated at 13:23 BST
Two reservists who died in the Brecon Beacons were taking part in the selection process for the Territorial SAS, the BBC understands.
The two soldiers were on a training exercise on the hottest day of the year in Powys on Saturday.
A third is in a serious condition after Saturday's incident which is thought to involve six soldiers collapsing in hot weather.
The Ministry of Defence (MoD) refused to comment on reports.
Eyewitness Nathan Webster took some pictures of the emergency response.