A murder probe has been launched after 39 dead bodies - including a teenager - were discovered in a lorry in Essex.
Paramedics rushed to the Waterglade Industrial Park in Grays at 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 all adults apart from one teenager, but emergency services have not identified any of the bodies yet.
The horrific find has sparked one of the biggest murder investigations in British history - and was described by police as an "absolute tragedy".
Detectives 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.
Road Haulage Association Chief Executive Richard Burnett said the container appeared to be a refrigerated unit and described conditions for anyone inside as "absolutely horrendous".
Temperatures in such units can be as low as -25C if frozen products are being transported, causing humans to "lose their lives pretty quickly", he said.
He went on: "It's going to be dark. If the fridge is running it's going to be incredibly cold.
"The only place to go to the toilet is on board the back of the trailer. You can imagine if they've been in there for days then there will be feces, there will be urine."
Bulgaria's foreign ministry said it could not confirm whether the truck had started its journey from the country.
"We are still checking the information, published in the British media and we're contacting the authorities," foreign ministry spokeswoman Tsvetana Krasteva said.
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."