Reports Wednesday that British police found 39 people dead in a truck container at an industrial park in the United Kingdom elicited an outpouring of condolences alongside condemnation of immigration policies across Europe.

Amnesty International of Ireland, in a tweet, offered its sympathy to families and friends of the deceased and suggested the "heartbreaking and horrifying" incident is an indictment of inhumane immigration policies.

"People who are forced to take dangerous journeys to reach Europe, in this case the U.K., often do so," the group wrote, "because current immigration policies deny them safe and legal options."

Shocked to hear of the deaths of 39 people found in a lorry container in Essex. The loss of life is incredible. Each had their own story, their own loved ones. Don't think of them as a number, but as people who were desperate to come to the UK and diedhttps://t.co/jBDS1vB66y — Jasvir Singh (@_JasvirSingh) October 23, 2019

Stephen W. Thrasher, an American writer and faculty member at Northwestern University's Medill School of Journalism, tweeted that "this is the reality borders create."

This is beyond horrific. https://t.co/en8fV4YEkD — Christian Christensen (@ChrChristensen) October 23, 2019

Authorities were called to the Waterglade Industrial Park on Eastern Avenue in Grays early Wednesday, according to a statement from Essex deputy chief constable Pippa Mills.

"Emergency services attended but sadly all 39 people inside the container had died," Mills said. "Early indications suggest that one of these people was a teenager, the rest are believed to be adults."

"A murder investigation was launched," she added. The truck driver, "a 25-year-old man from Northern Ireland, was arrested on suspicion of murder and remains in police custody."

Police believe the truck traveled from Bulgaria and entered the U.K. at Holyhead port in Wales on Saturday, more than 300 miles from where it was found by police Wednesday.

Seamus Leheny, Northern Ireland policy manager for the Freight Transport Association, told the Press Association that "if the lorry came from Bulgaria, getting into Britain via Holyhead is an unorthodox route."

The Bulgarian Embassy in London, The Associated Press reported, has agreed to work with the British authorities on the case.

"At present, it has not yet been confirmed whether the truck has a Bulgarian registration," Bulgaria's Foreign Ministry said. "British police have warned that the identification of the bodies will take a long time."

According to The New York Times:

By midday Wednesday, several police officers guarded the cordoned off area on Eastern Avenue, which was sealed off with fences covered with green tarpaulin. Police officers and forensic specialists were still inspecting the truck and had erected two tents alongside it. While the circumstances that led to the deaths remained unclear, early signs suggested a people-smuggling endeavor gone tragically wrong. But if the truck were being used to traffic migrants into Britain, the route would be atypical.

The U.K.'s National Crime Agency (NCA), which investigates organized immigration crime and human trafficking, acknowledged the "tragic incident" Wednesday and confirmed that the agency had deployed officers to assist with the case.

"We are working with partners including Essex police and immigration enforcement to provide specialist support to urgently identify and take action against any organized crime groups who might have played a role in causing these deaths," said NCA.

Essex Police, in a follow-up statement Wednesday, announced "a casualty bureau for people to call if they are concerned about relatives." The telephone numbers are 0800 056 0944 for callers located in the U.K. and 0207 158 0010 for callers from outside the country.