One of the country’s largest mental health and community trusts has pleaded guilty to breaching health and safety law over the death of a teenage patient.

Southern Health Foundation Trust admitted the charge, which was brought by the Health and Safety Executive, at Banbury magistrates court today. It was prosecuted under section 3 of the Health and Safety at Work Act 1974.

The prosecution was set up after 18 year old Connor Sparrowhawk drowned in a bath following an epileptic fit while he was in the care of the trust at Slade House in Oxford in 2013.

In a statement issued after today’s hearing, Julia Dawes, interim chief executive of the trust, said Mr Sparrowhawk’s death was “entirely preventable”.

She said: “Connor’s loss continues to have a devastating impact on his family and we are truly sorry that we didn’t keep him safe.

“The effect of Connor’s death has been far reaching and whilst it in no way compensates for the loss his family has suffered, it has led to significant changes and improvements in the trust.”

Ms Dawes said there had been times when the trust’s actions “unintentionally added to the distress of Mr Sparrowhawk’s family”. She said his death is a “constant reminder” of why the trust needs to improve its services.

An HSE spokesman said it would not comment until after sentencing on 12 October. The date is the same as another sentencing for the trust following its guilty plea to a Care Quality Commission prosecution over safety failures at Melbury Lodge, Royal Hampshire County Hospital, Winchester.

That prosecution was brought against the trust after a patient broke his neck when he fell from the roof.

It was the first time the CQC has used its regulatory powers to bring a prosecution against a trust.