A hotel has been evacuated after a burst water main caused flooding near King's Cross Station in the early hours of Sunday.
London Fire Brigade (LFB) said eight fire stations and about 60 firefighters were responding to the incident, which was affecting an area of around 250 square metres, on Pentonville Road.
About 20 people at a nearby hotel were evacuated by crews due to flooding, while the basements of "multiple" homes and commercial properties had been affected, LFB said.
The brigade was called at 04:07 BST, and said on Sunday afternoon that floodwater was "receding" near King's Cross but traffic would continue to be "heavily impacted".
LFB has deployed mobile flood barriers and specialist water rescue crews to the scene.
Pentonville Road is closed to traffic between Penton Rise and King's Cross Road.
Islington Council has urged people to avoid the area while crews respond, while stores - including Sainsbury's - on the road have been advised to close temporarily by emergency services.
Transport for London said 11 bus routes were on diversion on Sunday.
They are bus routes 17, 30, 46, 63, 73, 91, 205, 214, 259, 390 and 476.
Thames Water said it was "sorry to customers who have been affected" by the burst water pipe.
It added that engineers were on site, while support teams were helping affected customers.
"Our engineers have identified the burst, closed the main flow of water from the broken pipe and have had to temporarily close a section of the road so they can work safely, and the excess water can drain away," it said in a statement.
In February, the water firm announced a £20m project to update Victorian pipes in the area over the next three years.
Tina Hodgkinson, who lives in Killick Street, off Pentonville Road, said she was woken up at about 04:00 by what she thought was heavy rain.
"I looked out the window and it wasn't raining, but I could see there was this stream of water going down Pentonville Road," she told the OceanNewsUK.
While she said a cordon had been put in place where the street connected with Pentonville Road, her home had not been affected by flooding or water outages on Sunday morning.
LFB said firefighters were using a drone to survey the area affected by floodwaters, and traffic in the local area would be "heavily impacted".
Crews from Euston, Islington, Soho and surrounding fire stations were at the scene on Sunday.
The Metropolitan Police said officers were assisting fire crews, while the council said members of its emergency response team were also on site.
