Thousands of people have been left without water and several evacuated after a mains pipe burst as frozen systems begin to thaw.
London Fire Brigade were called to Camden, north London, at around 2.50am as shock footage showed flowing water up to the wheel arches of cars.
Thames Water has assured crews are working on the emergency situation - although they are unsure when customers will be reconnected to the network.
Meanwhile around 25 people have been led to safety by fire crews as eye witnesses described the residential road as a “river”.
A spokesman for the water firm said: “Our engineers have shut off the flow from a large burst pipe in Loudoun Road - it’s taken time to achieve this safely, as they needed to switch off a number of valves at different locations, some of which were under parked cars or submerged by flood water.
“They also needed to make sure when operating them that this didn’t lead to a further burst pipe elsewhere.
“We have loss adjusters and support staff at Swiss Cottage Library, where Camden Council is running a rest centre. They’ll be talking to residents who’ve been flooded, to help get their lives back on track.
Now that we’ve been able to turn off the water, we’ll focus on refilling the network – we don’t yet know how long this will take but will update you as soon as we can.
In the meantime, customers who are without water should still be able to use their heating.
“We’re really sorry for the flooding and distress this has caused.”
The fire brigade's 999 Control Officers have taken 18 calls related to this morning’s flooding.
Crews from West Hampstead, Kentish Town, Euston, North Kensington and surrounding fire stations are at the scene.
Station Commander Gary Deacon added: "This is a significant flooding that has affected around 100 properties and left thousands without water.
“Shift water rescue crews used boats to move around 20 people to upper floors of properties. Three adults and a child were evacuated to a place of safe haven.
“A number of residents have decided to remain in their properties and we’re patrolling the affected area to assist any further people who require assistance.
"There are numerous road closures in place and we're asking people to avoid the area where possible.
"The water authority are working to isolate the burst water main and firefighters are expected to remain at the scene throughout the afternoon.
"Crews are using flood barriers and a high volume pumping unit to divert flood water.
"A rest centre has been set up for affected residents at Swiss Cottage Leisure Centre."
