Fire is not a common threat. When a fire does occur, however, it usually has serious consequences. This is because fire and smoke can cause major damage. While electrical fires are the most common cause of fire within IT operations areas, a fire outside of an IT operations area— especially in support areas involving the power supply (including EPS and UPS) or the air conditioning system—can have numerous other causes. If an IT operations area, its support areas, or other neighbouring areas have inadequate fire protection, a fire can spread quickly. In addition, fires that start outside could spread to a data centre.