British police said the bodies of 39 people have been found in a container of a truck on Wednesday in Essex, southeast England.
The dead included 38 adults and one teenager, who was discovered in the early hours of Wednesday morning, the Essex Police said in a statement.
The ambulance service was called to Waterglade Industrial Park in Grays, Essex only 22 miles east of central London, where the victims were pronounced dead.
The bodies were found in a shipping container on the back of a semi-truck parked on the side of the road where police are now conducting their investigation.
The police have launched a murder investigation and have arrested the driver of the truck, a 25-year-old resident of Northern Ireland, on suspicion of murder.
The police said they believed the lorry arrived on Saturday from Bulgaria and entered the U.K. at the port in Holyhead, North Wales, more than 300 miles northwest of Essex.
It remains unclear the nationalities of the victims.
This is in spite of pending Brexit plans, both Britain and Bulgaria are currently members of the European Union and therefore Bulgarian nationals are permitted free entry to the U.K. Deputy Chief Constable Pippa Mills said Wednesday morning that the identification of the victims was the number one priority for the police.
"This is a tragic incident where a large number of people have lost their lives," Chief Superintendent of Essex Police Andrew Mariner said in the statement. "
Our inquiries are ongoing to establish what has happened."
