During the cross-Channel trip on board the Clementine, the group had desperately tried to raise the alarm, even calling the Vietnamese emergency number, as they ran out of air.
When they found there was no mobile phone signal in the trailer, some recorded goodbye messages to their families.
Nguyen Tho Tuan, 25, told his family: "I am sorry. I cannot take care of you. I am sorry. I am sorry. I cannot breathe.
"I want to come back to my family. Have a good life."
A metal pole had been used to try to punch through the roof of the refrigerated container, but only managed to dent the interior.