This is a rare and appalling incident whereby a young man has lost his life and a young woman remains in hospital fighting for her life.
An investigation is under way into the circumstances of exactly what has happened but I'd appeal to anybody that is staying at the caravan park or lives in the immediate vicinity that heard any commotion or witnessed any part of the incident to contact police.
Officers working on the inquiry are searching for the knife that they believe was used in the attack but this remains outstanding at this time.
Anyone with any information was urged to contact Lancashire Police on 101 or CrimeStoppers anonymously on 0800 555 111.
More top news
ITV News travels to Jordan to report on the growing global threat of the spread of deadly drug-resistant 'super bugs'.
The plight of Honduran migrants searching for safety has been harshly criticised by the US president.
Avicii, whose real name was Tim Bergling, was found dead in Muscat, Oman on Friday, according to his agent.