Ten fire engines and two fire rescue units, around 78 firefighters, are at the scene of a burst water main in Eversholt Street, Euston.
Flooding to a depth of three metres has affected a number of properties. Eversholt Street is closed while crews work to reduce flooding. A number of bus services are affected.
The Brigade was called at 0611. Fire crews from Soho, Islington, Kentish Town, Paddington and surrounding fire stations are at the scene.