Around 50 properties have been damaged and four people rescued after a 36-inch water main burst in north London.
Emergency services were called to the scene in Islington just after 7am on Monday after a 4ft deep flood washed through Hornsey Road.
The London Fire Brigade (LFB) later clarified that the burst water main caused a 3ft deep flood and two sinkholes.
Ten fire engines and around 70 firefighters were called to the scene, with crews helping two adults and two children to safety after they were unable to leave the flat, the LFB said.
The two adults and two children were not injured.
Fire crews have now begun to withdraw from the scene, but further road closures are expected to be in place “for some time” as repairs are carried out, the brigade added.
Station boss Matt Brown, who was at the scene, said: “Flood water affected Hornsey Road, Tollington Road and a leisure centre.
“There is severe congestion in the area and several road closures are expected to be in place for some time while our partners work to carry out repairs. People are urged to avoid the area.
“Firefighters used flood barriers to divert water and helped two adults and two children to safety. No injuries were reported.
“If you are affected by floodwaters, if possible (and without endangering yourself) move to a higher level.”
Thames Water, which supplies water to the area, remains at the site.
A spokesperson for the water company said: “We apologize for customers who experienced lower than normal pressure or no water today due to a burst pipe and the disruption this has caused.
“Our engineers were quickly on site this morning and stopped the water flow.
“We have used temporary pumps to restore water pressure levels and most customers should be back on supply and have water pressure back to normal.
“We are starting the repair and our customer teams are supporting those affected by the explosion.
“We have also proactively contacted anyone in the affected area who has pre-registered with us who has special requirements, such as being medically dependent on water, so that we can ensure we provide them with the help and support they need.”
Chris Dodsworth, a civil servant who lives in the area, described the situation as “quite stressful”.
He told the PA news agency: “I woke up around 7.30am and realized I could hear the sound of running water outside, which was obviously strange, especially given the weather recently.
“My first thought was that it had rained overnight, but then I apparently looked out of the window and saw that the whole street and connecting roads were completely under water.
“It’s so strange to be around so much water (especially in this dry season) … what a day of contrast.”
Liz Clutterbuck, 41, a vicar at Emmanuel Church, told the PA: “The flood is all the way to Arthur Road. The houses between Arthur Road and Tollington Way have water over the bottom of their front doors.
“Sobell (Recreation Center) is flooded by several feet – could see it at least two feet high on the outside exits in the parking lot. The water still seemed to be flowing fast an hour ago.”
Pastor Clutterbuck added that the church is open for residents to use if they need to.
A worker for the Tollington Arms, in Hornsey Road, said: “It happened at around 7am and within minutes it was flooding like a tsunami.
“The fire service was down very quickly and we hope, along with Thames Water, they can get things back to normal as quickly as possible.”
A spokeswoman for GLL, the social enterprise charity that runs Sobell on behalf of Islington Council, said the downstairs of the building was flooded, prompting staff and customers to be evacuated and closed for the day.