A man in his 40s has died in hospital following a serious assault in Dublin early on Friday morning.Gardaí said they are investigating the now fatal incident, which occurred at Parslickstown Drive, Mulhuddart, Dublin 15 at about 3:55am.Following the assault, a man was brought to hospital to be treated for serious injuries, but has since died.The office of the local coroner has been notified and a postmortem will be carried out in due course, said gardaí.This investigation is being co-ordinated from an incident room at Blanchardstown Garda station under the direction of a senior investigating officer. A family liaison officer has been appointed to the family.Gardaí are appealing for any witnesses or anyone with information in relation to this incident or who may have video footage – includi