On 23 October 2019, shortly after 01:40 BST, the East of England Ambulance Service responded to a 999 call from lorry driver Maurice Robinson, who had found 39 bodies inside a refrigerated articulated trailer parked on Eastern Avenue at the Waterglade Industrial Park in Grays, Essex. All 39 victims — 31 men and eight women, including 10 teenagers, the youngest two aged 15 — were pronounced dead before ambulance staff arrived. Post-mortems later gave a provisional combination of hypoxia and hyperthermia as the cause of death. The victims were initially believed to be Chinese nationals, but on 2 November 2019 Essex Police confirmed all 39 were Vietnamese. By 7 November all had been formally identified, with hometowns later released spanning Nghệ An, Hà Tĩnh, Hải Phòng, Quảng Bình and Thừa Thiên-Huế provinces.
The trailer had been loaded onto a ferry at Zeebrugge, Belgium, and shipped to Purfleet, Essex, arriving around 00:30 on 23 October, where it was collected by a lorry cab believed to have travelled from Northern Ireland via the Republic of Ireland and Holyhead. Essex Police led an investigation described as the largest mass-fatality victim-identification effort in the force's history, working with authorities in Belgium, Ireland and Vietnam. The National Crime Agency raised the possibility of organised crime involvement, and Belgian, Irish and French authorities separately opened related investigations, including a cross-border operation coordinated by Eurojust that led to 26 arrests in France and Belgium in May 2020.
Maurice Robinson, the driver who discovered the bodies, pleaded guilty to conspiring to assist illegal immigration and to the manslaughter of the 39 victims, and was sentenced to 13 years and 4 months. Ronan Hughes, described in court proceedings as a ringleader, pleaded guilty to manslaughter and was sentenced to 20 years. Gheorghe Nica and Eamonn Harrison were found guilty at the Old Bailey of manslaughter and related offences, receiving 27 years and 18 years respectively. Christopher Kennedy, Valentin Calota and Alexandru-Ovidiu Hanga were convicted of conspiring to facilitate unlawful immigration, receiving sentences of seven years, four and a half years and three years respectively. Gazmir Nuzi received a 10-month sentence for a limited role. Later UK convictions included Dragos-Stefan Damian (three years ten months), Marius Draghici (12 years 7 months) and Caolan Gormley (seven years). In total, 11 people were convicted in the United Kingdom in connection with the deaths.
In Belgium, 19 people were convicted in January 2022 of participating in a people-smuggling ring linked to the case, including ringleader Vo Van Hong, sentenced to 15 years. Those convicted, mostly Vietnamese or Belgians of Vietnamese origin, were accused of supplying, transporting or acting as look-outs for the migrants. Vietnamese authorities also arrested and charged several individuals in Nghệ An Province in connection with the smuggling network. Families of the victims subsequently faced difficulties and costs in repatriating the bodies, with international fundraising efforts helping cover expenses before all bodies were returned to Vietnam by the end of November 2019.