Emergencies that cause the deaths of large numbers of people can result from major accidents, natural disasters or acts of hostility. While what has happened cannot be undone, other people may be protected from similar events by careful investigation of the causes, the collection of evidence and the prosecution of any criminal acts. Within the wider investigation, responding to the deaths will focus on the respectful treatment and accurate identification of the physical remains, and where possible their return to the next of kin. A large number of deaths or complexity of circumstances, such as fragmentation of bodies, may require the deployment of an emergency mortuary. This can enable large volumes of specialist forensic tasks to be conducted, but will place new demands on the emergency services and local authority, including the need to consider body storage, specialist equipment, staffing, mortuary deployment and on-site maintenance, and mortuary integration with the local physical infrastructure and management arrangements. This will require a coordinated multi-agency approach. The decisions taken and the ways in which information is communicated may have a lifelong impact on the friends and families of those who have died. Plans should therefore be considered carefully from their perspective.