These incidents happen all over the world 24/7, they are then professionally investigated to find the cause and then hopefully limit the risks in the future, driver ban, road camber, road markings. A starting point for the investigation could be the container appears to have removed itself from the trailer, I have seen many in Thailand with faulty or no. Locking mechanism and the container bouncing away merrily on the trailer. Investigator start with the locking mechanism if it is faulty or not being used, corporate manslaughter.