A residential home had "systemic" failures before a 16-year-old boy drowned on a trip to an old sand quarry, a court heard.

Castle Homes Limited, which ran Castle Lodge home for young people in Cambridgeshire, admitted breaching health and safety over the death of Leyton teenager Umar Balogun in July 2013.

Two support workers also faced charges over Umar’s death, but were cleared following a trial at King's Lynn Crown Court.

At a sentencing hearing at last week at the Old Bailey, prosecutor, Quentin Hunt, of the Health and Safety Executive, said the company had pleaded guilty in April last year.

Outlining the case, Mr Hunt said employees of the home had taken boys on a trip to Bawsey Pits near King's Lynn on July 16 2013.

The staff made no efforts to stop Umar and another boy from getting into the water even though there were a number of "no swimming" signs.

Mr Hunt said: "Mr Balogun was seen to duck under the water and did not reappear.

"Mr Balogun may have got caught out by the changing depth. He subsequently became entangled in weeds and drowned.

"A diver was sent to the scene and subsequently recovered the body."

Castle Lodge offered one to one care of youngsters who "showed signs of sexually inappropriate behaviour", the court heard.

Mr Hunt, also told the court that while there were "generic risk assessments", individual assessments were not made for trips like the one to the pits.

The lawyer said there was "systemic failure" at Castle Lodge over a "long period" of time.

He added: "The failings of the company amount to high culpability. The company was directly and immediately responsible for the trip from the home which resulted in the fatal accident."

He highlighted "inadequate" training and induction of staff and said ad hoc trips had no proper risk assessment.

The prosecution asked for costs of more than £21,000.

Judge Mark Dennis QC indicated that he would reserve sentencing after considering the case.

Mitigating, Angus Withington said Castle Lodge was shut down "effectively as a moral decision" as it was thought to be "the right thing to do".

He outlined changes the company had made in the wake of the accident.

They included a requirement for temporary staff to read health and safety documentation, enforcement of "group leader responsibilities", and training in "dynamic risk assessment".

The barrister added that there was a system of discussing weekly activities well in advance which could not be changed without "written authority of the registered manager".

Sentencing will take place on Friday (March 10).