Scores of mobile phones were found in the lorry belonging to the people who died.
They had used their phones to see in the darkness and to try to message loved ones, in vain, as they slipped away. One of the phones belonged to 26 year old Pham Thi Tra My.
It is over a year since her parents found out about their daughter's death. On the living room wall of their house, in the Can Loc District of Vietnam's central Ha Tinh Province, there is a shrine to Tra My. The flowers on the shelf around her photograph are freshly cut.