Early Wednesday morning, authorities discovered a tractor-trailer in Essex, England containing 39 bodies. Police aren’t sure of the nationalities of the deceased and expect identifying them will be a lengthy process. The NY Times reports the two sections of the truck followed different routes to enter the country:

The police initially said they believed the truck had entered Britain at the port of Holyhead in Wales on Saturday, but later clarified that only the Bulgarian-registered tractor — the front of the truck, with the driver’s cab and engine — had traveled that route.

The cargo trailer it was pulling had entered Britain at Purfleet, a shipping port near Grays, where it was collected by the driver early Wednesday, they said.

Police believe the container came from Zeebrugge in Belgium and arrived in Britain shortly after 12:30 a.m. Wednesday…

While the circumstances that led to the deaths remained unclear, the trailer appeared to be refrigerated.

Such containers are typically tightly sealed, said Dave Wood, a former director general of British immigration enforcement, creating the risk that anyone traveling inside one could die of suffocation.

The BBC reports the identity of the driver:

The lorry driver, named locally as Mo Robinson, 25, from the Portadown area of County Armagh, Northern Ireland, has been arrested on suspicion of murder…

Richard Burnett, chief executive of the Road Haulage Association, said the container appeared to be a refrigerated unit, where temperatures could be as low as -25C.

He described conditions for anyone inside as “absolutely horrendous”.

CNN reports smugglers are taking greater risks using refrigerated trucks and cargo containers to transport people because new technology has made the crossing from France much more difficult:

Today, with more stringent border checks in place — utilizing technology like thermal imaging cameras to identify migrants hidden within vehicles — the option has become much more difficult and costly to attempt, with smugglers charging thousands of euros for passage.

“The UK has invested a lot of money in protecting the lorry routes” from migrants crossing from France, said Nando Sigona, an associate professor in international migration at the University of Birmingham told CNN earlier this year. “That route has probably been sealed off, or made more difficult to pursue.”

I’ll update this story if there are significant developments during the day. For now, here’s a Sky News report from earlier this morning: