Two remand prisoners are believed to have hanged themselves in custody in Northern Ireland.
Samuel Carson, 19, was found collapsed on the floor of his cell last night at Hydebank Wood Young Offenders Centre and Prison in south Belfast. Efforts by prison staff to revive him failed. He was awaiting trial accused of raping and sexually abusing a teenage girl over three days last year.
Frances McKeown, 23, was found on the floor in her cell a few hours later during a routine check by staff in the women's section of the prison.
The deaths are the latest in a series of suicides in prisons, which has led to major reforms to try to prevent them from happening.
Director general Colin McConnell said: "Yesterday's tragic events at Hydebank Wood have stunned everyone and there is deep sadness across the service."
The deaths are being investigated by the police, coroner service and Prisoner Ombudsman Pauline McCabe.
Carson was discovered by staff during the unlock of offenders in a part of the Young Offenders Centre known as Elm 1 just after 5pm yesterday. McKeown was found at around 8.30pm during a routine check by staff in a part of Hydebank known as Ash 4 which houses female inmates.
Mr McConnell added: "At this very difficult time I offer my sympathies to both the Carson and McKeown families. They are in the thoughts and prayers of our entire service.
"I also want to recognise the efforts made by the staff who were on duty at the time, who did everything they could to bring about a different outcome."
Carson was from Hesketh Road in north Belfast. He appeared at Belfast Magistrates' Court in March last year accused of raping and sexually abusing a girl aged 15 over three days. He was also charged with making indecent images of a child on the same dates.
According to Prison Service annual reports, during the year 2009/10 there were 190 incidents of self-harm across all sites as well as one death in custody awaiting an inquest.
In 2008/09 there were three deaths in custody awaiting inquest. In 2007/08 there were two deaths in custody awaiting inquest, and in 2006/7 there was one death in custody awaiting an inquest and one confirmed suicide.
In July 2008, Colin Bell, 34, hanged himself at the high-security Maghaberry prison, Co Antrim, while on suicide watch.
Hydebank accommodates all male offenders aged between 17 and 21 years on conviction, serving a period of four years or less in custody, and all female prisoners including young offenders.
Women transferred from Mourne House, Maghaberry, to Hydebank Wood in June 2004. Female immigration detainees are also held in the unit.
The governor at Hydebank is Gary Alcock and he has 382 staff to deal with 306 prisoners in single-cell accommodation, the Prison Service website said.
The service has a suicide and self-harm prevention policy which aims to identify those potentially at risk, encourage vigilance by staff and ensure the inmates are managed by skilled people and treated appropriately.
The policy includes reviews of the physical environment to reduce the opportunity for suicide, as well as anti-bullying measures.
Juliet Lyon, director of the Prison Reform Trust, said: "The deaths of these two young people are a tragedy, for them, their families and the Northern Ireland prison service.
"The only thing we can hope is that a thorough-going investigation into these young deaths will shed some light on the needs of vulnerable young people caught up in the criminal justice system and ways to avoid future tragedy."
Nationalist SDLP South Belfast assembly candidate Conall McDevitt said the deaths show a serious crisis with the Prison Service and management at Hydebank.
He called on Justice Minister David Ford to make a statement on the double tragedy.
"Due to the seriousness of the incident, there must also be a separate, fully independent investigation into these extremely serious and tragic incidents," he added.