The bodies of 39 people have been found in a lorry container in Essex.
Police were called by the ambulance service shortly before 01:40 BST after the discovery at Waterglade Industrial Park in Eastern Avenue, Grays.
The lorry driver, a 25-year-old man from Northern Ireland, has been arrested on suspicion of murder.
Essex Police said the vehicle travelled from Bulgaria and entered the country via Holyhead, Anglesey, on Saturday.
Early indications are that 38 adults and one teenager have died, the force said. Police would not say whether any survivors were found in the lorry.