A haulier has admitted the manslaughter of 39 Vietnamese migrants who were found dead in the trailer of a lorry in Essex.Ronan Hughes, 40, is one of several men accused of being part of a people-smuggling ring linked to the tragedy last October.He admitted 39 charges of manslaughter at the Old Bailey in London on Friday.Prosecutors alleged Hughes, of Co Armagh in Northern Ireland, played a leading role by allowing his trailers and drivers to be used in human trafficking.The bodies of the