A murder probe has been launched after 39 bodies - including a teenager - were discovered in a lorry in Essex, UK.
Emergency services rushed to the Waterglade Industrial Park in Grays at around 1.40am this morning.
When they arrived they found the bodies of 39 people in the back of the vehicle.
It's believed the victims are 38 adults and one teenager, but it's unclear who they are or exactly how they came into the country.
The horrific find has sparked one of the biggest murder investigations in British history.
Police believe the vehicle was travelling from Bulgaria and entered the UK three days ago via Holyhead in Wales, one of the main port for ferries from Ireland.
A 25-year-old lorry driver from Northern Ireland has been arrested on suspicion of murder.
The crime scene is just a short distance from intu Lakeside shopping centre and the M25 Dartford Crossing.
Chief Superintendent Andrew Mariner said: "This is a tragic incident where a large number of people have lost their lives. Our enquiries are ongoing to establish what has happened.
"We are in the process of identifying the victims. However, I anticipate that this could be a lengthy process.
"We believe the lorry is from Bulgaria and entered the country at Holyhead on Saturday 19 October and we are working closely with our partners to investigate.
"We have arrested the lorry driver in connection with the incident who remains in police custody as our enquiries continue. I appreciate this cordon is going to disrupt the activity of local businesses in the area and we will work to ensure that disruption is kept as short as possible.
"We are working with Thurrock Council to mitigate against any impact our investigation scene will have locally."
In a tweet published shortly before 10.30am Prime Minister Boris Johnson said: "I’m appalled by this tragic incident in Essex.
"I am receiving regular updates from the Home Office & will work closely with Essex Police as we establish exactly what has happened. My thoughts are with all those who lost their lives & their loved ones."
Glen Freeland, from GSF Car Parts which is close to where the bodies were found, said staff could not access the shop on Eastern Avenue on Wednesday morning.
"The manager went to get into work this morning and it was cordoned off and we've been moved to a different area," Mr Freeland said.
"All we know is they found the bodies in the back of a lorry.
"It was a bit of a shock but we're not 100 per cent sure of what's happened."
A restaurant worker in the industrial estate, who did not want to be named, said: "There's a lot of police and forensics.
"We've just seen what has been said online. It's awful.
"We thought maybe someone had broken into a lorry, but it's just awful."
Paige Wade was driving past the industrial park at 4.15am on the way home from work.
She told the PA news agency: "I honestly didn't see much, I had just finished work while driving up Motherwell Way and all you could see was blue flashing lights, as I was driving past there was police tape to cordon off the start of eastern avenue.
"I knew it was serious because of how many police cars and ambulances were there, but the police had parked their cars across the whole access of the road so you couldn't see anything.
"There's always lorries around there as they park up there for the night, I couldn't say whether I did or didn't see the actual lorry in question."
A cordon has been put in place and access to and from the Waterglade Industrial Park remains closed.
Nine police cars and fifteen police officers have been stationed at the scene, which is close to the shopping location Lakeside.
Charlie Duggins-Jones described travelling past the scene on the way to work this morning.
"When I saw that the road wasn’t just closed off to access, but curtained off from view, I knew it would be something bad, but not this awful," he said.
"It’s incredibly shocking being so close to where you work, our whole industrial site is talking about it!
"It’s the last thing you expect to find when you come to work in the morning."
A statement regarding the discovery will be delivered by DCC Pippa Mills at Grays Police Station at 11.30am this morning.
Home Secretary Priti Patel tweeted: "Shocked & saddened by this utterly tragic incident in Grays.
"Essex Police has arrested an individual and we must give them the space to conduct their investigations."
Jackie Doyle-Price, MP for Thurrock, described tweeted her fury at the deaths.
"Sickening news of 39 people found dead in a container in Grays," she wrote.
"People trafficking is a vile and dangerous business. This is a big investigation for @EssexPoliceUK Lets hope they bring these murderers to justice."
Ferries sail out of Holyhead port to Dublin in Ireland.
It is the principal link for road vehicles to get from England and Wales to Ireland.
More than two million people travel through the port each year, which is operated by Stena Line Ports Ltd.
Seamus Leheny, Northern Ireland policy manager for the Freight Transport Association (FTA), told PA: "There is a direct route to Holyhead from Dublin.
"If the lorry came from Bulgaria, getting into Britain via Holyhead is an unorthodox route.
"People have been saying that security and checks have been increased at places like Dover and Calais, so it might be seen as an easier way to get in by going from Cherbourg or Roscoff, over to Rosslare, then up the road to Dublin.
"It's a long way around and it'll add an extra day to the journey."
Back in June 2000, the bodies of 58 Chinese immigrants were found in a lorry in Dover.
A Dutch driver was jailed the following year over their manslaughter.
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