LSgt Collins, a keen rugby player, from Tiers Cross near Haverfordwest, joined the Army at 16, and served with distinction in Northern Ireland, Bosnia and Iraq before going to Afghanistan.
Tonight's Panorama details how LSgt Collins was forced to make six-hour round trips for psychiatric appointments having to repeat the horrors that haunted him to different changes of staff.
Police in Hampshire were today continuing to probe the circumstances surrounding LSgt Parker's death.
It is understood LSgt Parker was sitting in the rear of the vehicle, which had a raised hard-top cover, when he fell on to the A35 heading towards Totton, at 11.50pm.
His sister Katie Burgan, colleague Guardsman Tony Byrne and boss Captain Irwin Clark also paid tribute to LSgt
Burgan before his coffin was carried from the church to Celine Dion's Because You Loved Me.
Many attending the service added red ties, shoes or handbags to their black outfits in honour of LSgt
Burgan's passion for Liverpool FC.
LCpl Redpath, 22, and LSgt Casey, 27, were travelling in a convoy to the north Rumaylaj oil fields, west of Basra, when the device exploded in the early hours of Thursday morning.
Married father-of-two LSgt Casey, from London, was on his second tour of duty in Iraq.
LSgt Rob Jones, 25, Anglesey: To everyone at home, having a whale of a time but looking forward to coming home.
LSgt Carwyn Bee, 28, Caerfon: Merry Xmas Nia, Iestyn, Cian and the family.
Having served in the Army for 11 years, LSgt
Cunningham knows a thing or two about war, and Afghanistan, he said, is far worse than anyone realises.
The statistics relating to IED deaths and injuries are grim, making LSgt
Braithwaite's role an unenviable one - the Ministry of Defence has previously said almost two-thirds of fatalities have been caused by IEDs.