A mother of four boys who died in a fire surrounded by excrement and rubbish while she went to Sainsburys failed to replace the battery in their smoke alarm, a court has been told.
Deveca Rose, 29, is accused of killing Kyson and Bryson Hoath, aged four, along with Leyton and Logan Hoath, aged three, who died in the inferno in Sutton, south London.
The fire started from either a discarded cigarette or an upturned tea light and spread to rubbish on the floor before engulfing the living room sofa, the Old Bailey heard.
Rose allegedly left the children alone to Sainsburys after being heard shouting and swearing at them by a neighbour.
The house was full of rubbish and social services had been working with the family but closed the case after Rose failed to co-operate, jurors have heard.
Rose denies four counts of manslaughter and one of child cruelty after the tragedy in Collingwood Road on 16 December 2021.
Kyson and Bryson Hoath, aged four, died alongside their brothers, Leyton and Logan Hoath at their home in Sutton, south London, in December 2021
The two sets of twins died after their mother Deveca Rose, 29, went out shopping leaving either a discarded cigarette or an upturned tea light in their living room, which was 20cm deep in rubbish
The Old Bailey heard Deveca Rose, pictured, had failed to replace the battery in their smoke alarm
She claims she had left the children with a woman called Jade.
Darren Woodhams, a fire investigator for the London Fire Brigade, found the fire started from a either a discarded cigarette or an upturned tea light, which set fire to rubbish on the floor and then a sofa in the living room.
The fire spread due to the amount of rubbish on the floor, the court heard.
Jurors were shown photographs of the floor of the living room which was covered in rubbish 20cm deep and littered with human excrement.
Giving evidence to the jury today, Mr Woodhams said: There was a smoke detector on the first floor landing however this was found to be inoperable and had no battery.
Four 999 calls were made to report the fire and eight fire engines attended.
Mr Woodhams added: The initial discovery of the fire was a passer-by who banged on the door of the neighbour telling them there was a fire.
It was the neighbours who made the first of four calls to the fire brigade and they informed the call operator children were inside.
Rose, pictured outside the Old Bailey, denies the manslaughter of her four sons who died in a fire at the family home in Sutton, south London in December 2021. She also denies child neglect
Darren Woodhams, a fire investigator for the London Fire Brigade, found the fire started from a either a discarded cigarette or an upturned tea light, which set fire to rubbish on the floor and then a sofa in the living room
Firefighters carried the four boys from the burning building but they were all declared dead a short time later
A neighbour forced the front door of the property open to try to access the children - however due to the fires intensity and location in the front room of the property they were unable to enter.
A childs voice could be heard repeating there is a fire here over and over, the court heard.
Firefighters entered the flat wearing breathing apparatus and found the four children unconscious.
They performed CPR on the children but they could not be saved,
Mr Woodhams said the property was a mid-terraced house of five metres by 15 metres.
Rose is not in court as she has an issue with her eyes and is observing the trial via a link from a room with lower lighting.
She denies four counts of manslaughter and one of cruelty to a person under 16.
The trial continues.