Because the Chicago Fire Department handles the city's Emergency Medical Services, certain large-scale incidents, such as a major vehicle accident or a building collapse will require a special EMS Response. This response is also known as a "Plan" from the CFD's EMS Division. These plans consist of EMS Units and Fire Units, depending on the incident. EMS Plans can also be assigned to fires where a large EMS presence is needed or special events, such as a marathon where injuries may arise.