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
The wintry theme continues.
Violent clashes between police and protesters erupted in Athens ahead of a farmers protest against pension cuts.
A coroner has ruled a "series of failures" contributed to the death of a newborn.