Katie Thistleton meets survivors Usman Ahmed and Martin Hibbert, who are rebuilding their future four years on. Usman Ahmed was working his final shift at Manchester Arena, determined to tell his story and despite saving lives, the guilt of the people he could not save still haunts him. Martin Hibbert was paralysed from the waist down and is now looking to climb Kilimanjaro for a spinal injuries charity. A new friendship is born as Martin promises to help Usman find a way through his feelings and a new future. You will hear eye witness accounts, details of mental and physical injuries, post-traumatic stress and conversations from dark places. A list of organisations that can provide help and support is available at bbc.co.uk/actionline. Originally broadcast on BBC Radio Manchester. Producers: Sara Dumbell, Andy Bell, Kate Squire. Editors: Andy Bell, Liam Bradford. Online producer: Rachael Smith. Executive Producer: Kathryn Morrison.