13-year-old's stab death was 'random attack' A 13-year-old girl who was stabbed in a "random, isolated attack" dialled 999 as she lay dying from her injuries, police said tonight. Casey-Lyanne Kearney called police and a passer-by phoned for an ambulance, but despite their efforts she died in hospital hours later. A 26-year-old woman who was arrested on suspicion of murder remains in police custody. It has been confirmed that she was "known to a number of local public agencies." John Willis, who comforted Casey-Lyanne, was one of the first people to find the dying girl in Elmfield Park, Doncaster, South Yorkshire. He was alerted to her plight by his two sons who saw her lying on the ground in a semi-conscious state. He said: "I was expecting to find someone having a fit, she was on the ground lying on a coat, another woman was with her making sure she was cared for. We got her in the recovery position. She didn't move a lot and she didn't speak. Her breathing was very shallow and she was very pale. The police arrived very promptly and took over the situation. I was very upset, it was very shocking. Senior investigating officer Detective Superintendent Terry Mann of South Yorkshire Police said officers were attempting to establish the teenager's movements after she left her home in Rossington at around midday yesterday. He said Casey-Lyanne was intending to catch the bus to Doncaster town centre where she was going to meet a friend. He said: "South Yorkshire Police have launched a murder investigation after a 13-year-old girl died last night at 9.25pm in Doncaster Royal Infirmary (DRI) following what appears to be a random, isolated attack. We know that Casey-Lyanne Kearney left her home in Rossington around 12 noon yesterday and caught the number 55 bus into town to meet a friend. We are working to ascertain Casey's movements after leaving home. At 1.18pm Casey called police from inside Elmfield Park saying she'd been stabbed. She was treated at the scene by police and paramedics before being taken by ambulance to DRI. Mr Mann said Casey-Lyanne was 5ft 3in with long, straight, ginger hair. She was wearing a black waist-length coat yesterday, along with blue jeans and knee-high boots. She was also carrying a black Bench shoulder bag with purple writing. He appealed for any members of the public who were in or near the park at lunchtime yesterday, and either saw anything suspicious or Casey-Lyanne herself, to contact police. A specialist incident room has been set up which can be contacted on 01709 443510, or people can also call Crimestoppers anonymously on 0800 555 111. The park remained sealed off today and blue police tape was attached to railings and trees. Locals spoke of their shock at the stabbing. There have been a number of incidents in there, it is not like when I was a child," she said. She explained that her daughter had come across a drunk woman when she was walking close to the park yesterday afternoon. Doncaster Council chief executive Jo Miller said: "We are deeply saddened by this tragic event and our thoughts are very much with family and friends. She said the investigation was at an early stage and any member of the public who had any information should come forward.