During the 2020 UK Outbreak of COVID-19, Transport for London (TfL) services were reduced in stages. After growing concern that amongst the outbreak and despite government advice on social distancing, tube services were still crowded. All Night Overground and Night Tube services, as well as all services on the Waterloo & City line, were suspended from 20 March, and 40 tube stations were closed on the same day. The Mayor of London and TfL urged people to only use public transport if absolutely essential, so that it could be used by critical workers. The London Underground brought in new measures on 25 March to combat the spread of the virus, by slowing the flow of passengers onto platforms, which included the imposition of queuing at ticket gates and turning off some escalators. Even with these measures in place there was still criticism that, especially in rush hour, some stations and trains were still experiencing crowding; however, statistics showed that the tube was experiencing some of the lowest passenger journey numbers since the 1800s.