The Blitz. Balham, 8pm, October 14, 1940.

It was a month into the Blitz and the air raid siren sent hundreds of people scurrying to Balham station to shelter from Luftwaffe bombs.

As people huddled on the platforms below the drone of planes and rumble of bombs got closer until an enormous blast above stopped the chatter.

A bomb had smashed into the High Road, leaving a crater 50ft wide into which an omnibus - travelling as usual in darkness - fell.

Remarkably, none of its passengers were seriously hurt - and today the omnibus’s bruised shell poking out of the crater remains one of the iconic images of the Blitz - but the real nightmare was unfolding below.

The blast severed a water main, a gas pipe, a sewer pipe, and penetrated the north-bound tunnel of the Underground. Nearly seven million gallons of water poured into the tunnel and mixed with sand, debris and sewage.

The platform was buried under gravel and sand and within minutes, the water nearly reached the main concourse, some 25ft above.

Most in the tunnel were led to safety via escape holes, but many couldn’t escape and sank and drowned in a deluge of slurry.

A reports at the time said: “The [engineer] still has the scars on his hands caused by people tearing at them while he was trying to draw the bolts of the emergency hatch.”

The devastation was so great that rescue teams were still recovering bodies around Christmas, it wouldn’t be until after the new year that the Tube would be running again - the Government concealed the scale of the tragedy until after the war, for fear of creating panic among Londoners.

Those traumatic minutes have been well documented and brought to the eyes of millions in the Hollywood adaptation of Ian McEwan’s novel Atonement, starring Keira Knightley.

And, following an investigation by the Wandsworth Guardian, London Underground finally changed a plaque that incorrectly commemorated the dead.

The new plaque was unveiled following a ceremony at St Mary and St John the Divine Church last Thursday - which was attended by some bomb survivors.

To mark the 70th anniversary, we look at tales of courage and stoicism that shaped the followed in the minutes, hours, and days ahead...