CountyClean, in charge of the repair operation where the world's largest 'fatberg' was found, has taken a survey of the damage with a remote CCTV camera.
This footage is thought to show the beginning of the fatberg under the streets of London.
More top news
The 20-year-old was found fatally wounded on Roth Walk, near Finsbury Park, north London at around 3am on Saturday, Scotland Yard said.
Police have arrested a man wanted in connection with a burglary at the home of pensioner Richard Osborn-Brooks.
The rally comes after it emerged that the Home Office destroyed thousands of landing cards documenting the arrival of windrush-era migrants