A man throwing objects onto train tracks caused the suspension of the London Overground in west London.
Southern trains between Shepherd’s Bush and Clapham Junction were axed by the incident near Kensington Olympia.
The chaos hit Watford Junction to Clapham Junction services from Monday morning’s rush hour.
A Metropolitan Police spokesman said a man on a roof close to the track threw a number of items onto it, which has caused lines to be blocked. Disruption is now expected to last all day.
Juliette Smith, who lives in nearby Russell Garden Mews, said she and her neighbours had been evacuated by the police.
She told the Standard: “Some of the houses have been trashed. My neighbour has been in tears. The guy has been destroying roofs and skylights since 4am.
“The police are in my house they were thinking of going through the skylight to get him. He was shouting and throwing stuff.”
Local councillor Aarien Areti told the Standard: “The police are trying to negotiate but not successfully it seems.”
Another resident said: “They have to get him down, this is getting ridiculous.”
A London Fire Brigade spokesman said: “Firefighters are supporting colleagues from the Metropolitan Police Service at an incident on Russell Garden Mews, Kensington.
“The Brigade was first called about the incident at 10.19am, and crews from Hammersmith and Paddington Fire Station are currently on scene.”
National Rail added: “No trains are able to run between Shepherd’s Bush and Clapham Junction until further notice.
“This will affect Southern services between Watford Junction and East Croydon, with trains being cancelled or terminated short.
“Please allow an extra 30 minutes to travel as you will have to use an alternative route.
“Check journey planners and station screens for the latest information.”
Scotland Yard said: “Police were called at 04:21hrs to reports of a man on a roof in Russell Gardens Mews, W14.
“He threw a number of items down onto nearby railway tracks.”
