Fire resources are dispatched according to information received by the 9-1-1 Emergency Command Center (ECC) operator who will ask the caller questions to gauge the level of resources needed. Aided by a computer program, the ECC operator selects the closest available unit(s) to respond to an incident. Resources are generally sent on a worst case scenario, meaning that during fire season they will dispatch several fire engines, water tenders (tankers) and air support to a fire. Then when it is determined that the first resources on scene can handle it, others are canceled. This assures that there are enough initial resources on scene as quickly as possible should an incident be found to be severe.