In May 2012, the BTP formed the Medic Response Unit to respond to medical incidents on the London Underground network, primarily to reduce disruption to the network during the 2012 Summer Olympics. The scheme was initially for a 12-month trial, and consisted of 20 police officers (18 police constables and two sergeants) and two dedicated fast-response cars. The officers attached to the unit each undertook a four-week course in pre-hospital care, funded by TfL. TfL estimated that around one third of delays on the London Underground were caused by "passenger incidents", of which the majority related to medical problems with passengers; the purpose of the unit is to provide a faster response to medical incidents, providing treatment at the scene with the aim of reducing disruption to the network. The unit also aims to assist passengers who may be distressed after being trapped on trains while an incident at a station is resolved. Its training and equipment is the same as that of the London Ambulance Service in order to ensure smooth hand-overs of patients. At the end of the trial period, in October 2013, the unit was reduced to eight officers; the other twelve returned to regular policing duties after TfL judged the results of the scheme to be less than conclusive. Officers from the unit treated over 650 people in the first year of operation, including rescuing a passenger who fell onto the tracks, and made 50 arrests.