Facebook has activated its Safety Check feature as a 24-story tower block in London is engulfed in flames.
Grenfell Tower in Kensington caught fire during the night. Residents banged on neighbours' doors to wake them, but six people have been confirmed dead in the huge blaze, police told the BBC on Wednesday. The number is expected to rise with many people unaccounted for.
Facebook's Safety Check feature allows people to signal to friends and family they are safe during a large-scale disaster or incident. It was previously activated during terror attacks in London and Manchester.
Amid reports that fire alarms did not go off, The Guardian reports that residents of Grenfell Tower previously raised concerns about fire safety with the building's managers and local authorities.