London — The bodies of 39 people have been found in a truck in Essex, southeast England. The dead included 38 adults and one teenager, who were discovered in the early hours of Wednesday morning, the Essex Police said in a statement.

The ambulance service was called to Waterglade Industrial Park in Grays, Essex only 22 miles east of central London, where the victims were pronounced dead. The bodies were found in a shipping container on the back of a semi truck parked on the side of the road where police are now conducting their investigation.

The police have launched a murder investigation and have arrested the driver of the truck, a 25-year-old resident of Northern Ireland, on suspicion of murder.

The police said they believed the lorry arrived on Saturday from Bulgaria and entered the U.K. at the port in Holyhead, North Wales, more than 300 miles northwest of Essex.

“This is a tragic incident where a large number of people have lost their lives,” Chief Superintendent of Essex Police Andrew Mariner said in the statement. “Our enquiries are ongoing to establish what has happened.”

I’m appalled by this tragic incident in Essex. I am receiving regular updates and the Home Office will work closely with Essex Police as we establish exactly what has happened. My thoughts are with all those who lost their lives & their loved ones.

— Boris Johnson (@BorisJohnson) October 23, 2019

Prime Minister Boris Johnson said on Twitter he was “appalled” by the incident.

In 2001, a Dutch  truck driver was convicted of manslaughter for the deaths of 58 Chinese immigrants who suffocated in the back of his tomato truck that was found in Dover, southern England.

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