London's largest ever grass fire broke out three years ago today (July 15).

More than 200 firefighters tackled the blaze at Wanstead Flats, where more than 100 hectares of grass was alight at its height.

This is an area roughly the same size as 100 football pitches.

%image(15040580, type="article-full", alt="The aftermath of the "biggest ever" grass fire in London's history which broke out in Wanstead Flats last night. Photo: Ken Mears")

Smoke - visible for miles - drifted across busy roads and caused closures in the area.

The fire, which broke out about 4pm on a Sunday amid a heatwave in London, was still smouldering the following day as 100 firefighters remained at the scene damping down the earth.

The blaze prompted firefighters to urge the public to take greater care.

At the time, then-London Fire Commissioner Dany Cotton said: “This weekend we dealt with the largest grass fire in our history, as well as a range of other serious fires on grassland.

“Grass fires spread like lightning so if you see dry grass smouldering, please call 999 and report it immediately so that firefighters can deal with it and stop it from spreading.”

The community rallied together in support as the fire raged.

%image(15040584, type="article-full", alt="Firefighters spent four days tackling grass fires at Wanstead Flats last year. Picture: Ken Mears")

People offered to take in families temporarily evacuated from their homes and provided supplies to firefighters battling the blaze, which spread dangerously close to a petrol station in Aldersbrook Road.

In the aftermath, Wanstead Flats' iconic skylarks were thought to have escaped the worst of the fire as the ground-nesting species was living just south of the affected area.

But much of the habitat of the grassland’s other bird species was destroyed.

%image(15040586, type="article-full", alt="Firefighters tackle a wildfire in Wanstead Flats on July 15 2018, London's "biggest ever grass fire". Photo: Helen Mathias / EyeContact Photography")

The scale of the blaze meant its cause was not determined, but common causes of grass fires include dropped cigarettes, barbecues and glass and broken bottles, which can magnify the sun.

On the first anniversary of the Wanstead Flats blaze in 2019, firefighters warned that "one act of foolishness can have devastating consequences".

In August last year, two separate fires at Wanstead Flats damaged up to three hectares of grass and shrubland.