Four fire engines and around 25 firefighters were called to a fire on Kymberley Road at 3.31am today (April 24).
When crews arrived, flames were visible outside the underground car park.
Firefighters quickly brought a small fire on the lower ground floor under control.
One man was treated at the scene for burns by fire crews before being taken to hospital by the London Ambulance Service.
Crews from Harrow, Northolt, and Wembley fire stations attended.
The incident was declared over by 4.38am.
The cause of the fire is now under investigation by fire officers and the Metropolitan Police.
A spokesperson for the London Fire Brigade said: “Four fire engines and around 25 firefighters were called to a fire at an underground car park above a block of flats on Kymberley Road in Harrow.
“On arrival flames were showing outside the underground car park.
“Crews extinguished a small fire on the lower ground floor.
“One man was treated by fire crews for burns and was taken to hospital by London Ambulance Service.
“The Brigade’s 999 Control officers received their first call alerting them to the fire at 0331, they deployed crews from Harrow, Northolt and Wembley fire stations.
“The incident was over by 0438.”
The cause of the fire is under investigation by the Brigade’s fire investigators and the Met police.
