A lightning strike during the storms on the hottest July day on record caused a fire on Wimbledon High Street.
Most of a two-storey building containing a shop, flat and a clock tower was damaged by the fire. There we no reports of any injuries.
The Brigade's fire investigation team believe the fire was accidental and was caused by a lightning strike.
Fire Investigator Adrian Parker said: "We believe the lightning struck the clock tower which had a copper top and weather vain on it. It also struck the roof below.
"Fires caused by lightning are really uncommon but unfortunately can cause quite extensive damage."
The building was a fire station established in 1890 and housed a horse drawn steam pump called “The May Queen”.
The Brigade's 999 Control Officers took 15 calls to the fire.
The Brigade was called at 1812 and the fire was under control by 2144. Fire crews from Tooting, Wimbledon and Mitcham fire stations attended the scene.