The Great Smog of 1952 took hold on London exactly 61 years ago, claiming an estimated 4000 lives.
A spell of cold weather, combined windless conditions then gathered air particles mainly from the excessive use of coal, which then formed a thick layer of smog over the capital city. Daylight then turned in to dusk-like conditions as the fog crippled the city.
The smog lasted for five days causing major disruption throughout London.
A thick smog envelopes London causing many deaths and injuries London was blanketed by thick fog smogat Ludgate Circus. This picture was taken at 2pm.
A London Transport inspector holding a flare leads a bus out of the terminus at Aldgate East as dense fog again blanketed London, causing widespread traffic chaos.
Postman Robert Baker tests a new featherweight open-top smog mask. At the bottom of the mask is a small plastic tube that releases small amounts of ammonia from crystals to neutralise the atmospheric acids
Double-decker buses circle the Prince Albert statue at Holborn Circus in London, England, in the smog at night.
'A foggy Piccadilly partially lit by the light from a fruit seller's stall, 1952. Foggy London scene, 7 December 1952.
A tugboat on the Thames near Tower Bridge in heavy smog.
Monty Fresco/Getty Images
A man guiding a London bus through thick fog with a flaming torch.
A London bus makes its way along Fleet Street in heavy smog, 6th December 1952.
Mid-morning smog, as seen from the embankment at Blackfriars.
Heavy smog in Piccadilly Circus
Large numbers of people using the underground system to get around London during a period of heavy smog, which hampered transport on the roads.