A grisly discovery in the middle of night, and now a murder investigation.
Police have discovered 39 bodies inside a cargo truck container at an industrial park in Essex, England.
One teenager and the rest adults.
The driver -- who has not been publicly identified -- is under arrest.
Essex's deputy chief of police, Pippa Mills: (SOUNDBITE)(English) ESSEX POLICE DEPUTY CHIEF CONSTABLE, PIPPA MILLS, SAYING: "At this stage, we have not identified where the victims are from or their identities, and we anticipate this could be a lengthy process." While it's not yet clear who the dead are - or the cause of death - it is believed that the truck's journey began in Bulgaria and may have entered the UK through a seaport in Wales.
The grim scene was uncovered shortly shortly before 1:40 a.m.
On Wednesday (October 23) morning, after ambulance services made a call to Essex Police.
Police say the driver is a 25-year-old man from Northern Ireland.
The port in Wales, called Holyhead, is a major entry point for traffic from Ireland, the UK's only land border with the EU.
For years immigrants have attempted to traverse the UK and EU illegally by stowing inside the cargo, sometimes with fatal results.