When officers arrived they found a man with a stab wound to his stomach.
He was taken to hospital but, sadly, later died there.
A 42 year-old woman, two men aged 41 and 45, and a 15 year-old boy have all been arrested on suspicion of murder and are currently in custody.
Detective Inspector Kev Hughes, from the Kent and Essex Serious Crime Directorate, said: “I know this incident will concern people living around the Northlands Park area but I want to reassure them we do not believe there is an ongoing risk to the wider public.

“Officers acted swiftly to make arrests and our enquiries are ongoing.
“Uniformed officers, plain clothed detectives, and forensics experts will remain at the scene and you are likely to see an increased police presence in the area.
“I need anyone who saw anything or has any CCTV, dash cam or doorbell footage, or any other information, to contact my team.”
If you have any information you can contact Essex Police on 101 Please quote incident 114 of 11 July.
You can also call us on 101 or contact Crimestoppers anonymously on 0800 555 111.