Five teenagers have been arrested on suspicion of murder in connection with the fatal stabbing of a 15-year-old boy at a caravan park.
Michael Morgan was found unconscious in a mobile home at a council-run caravan park in Lancing, West Sussex, at 10am on Sunday. Paramedics pronounced him dead at the scene.
Four males, aged 19, 15, and two aged 16, and one 18-year-old woman were arrested and are being questioned, Sussex Police said on Monday.
Michael's family have spoken of their devastation at his death.
His mother, Helen Long, 35, of Nicholson Drive, Shoreham, West Sussex, said: "We are completely numb and still trying to take it in. I cannot believe what has happened.
She added: "Michael was a thoughtful and caring boy who could be very funny. He was popular, had lots of friends and was very sociable. He was a much-loved son who is going to be missed and will always be in our heart."
Sussex Police Detective Chief Inspector Adam Hibbert said: "We are aware from our inquiries so far that a group of young people, who knew each other, had gathered together inside a mobile home on Saturday evening to enjoy themselves.
"It is possible that some of the young people may not yet be aware of what has happened and may not have spoken to detectives.
"I would ask that they make contact with my team, to help us piece together the circumstances which have tragically led to the premature death of a young person."
Anyone with information should contact the Major Incident Suite in Littlehampton on 0845 60 70 999 quoting Operation Firle, or call Crimestoppers, anonymously, on 0800 555 111.
