Charlie Gard's parents have ended their legal fight over treatment for their terminally-ill baby son, saying: "We are sorry we could not save you."
Chris Gard and Connie Yates announced their decision as a High Court judge was preparing to oversee the latest round of a five-month legal battle.
Reading a statement, Ms Yates told the packed courtroom from the witness box: "This is one of the hardest things that we will ever have to say and we are about to do the hardest thing that we'll ever have to do, which is to let our beautiful little Charlie go."
She said "a whole lot of time has been wasted" and said she hoped Charlie's life would not be in vain.
Ms Yates wept as she said: "We are sorry we could not save you."
Charlie suffers from a rare inherited disease - infantile onset encephalomyopathy mitochondrial DNA depletion syndrome (MDDS) - and his doctors at Great Ormond Street Hospital for Children (GOSH) in London have argued that he should be allowed to die with dignity.
But his parents wanted him to be given an experimental treatment by specialist Michio Hirano, a professor of neurology at Columbia University Medical Centre in New York, who travelled to London last week to examine Charlie for the first time and discuss the case with Great Ormond Street doctors.
On Friday lawyers for GOSH told the High Court that the latest scan carried out on Charlie made for "sad reading".
On Monday, Mr Justice Francis had been scheduled to analyse what his parents said was fresh evidence at a hearing in the Family Division of the High Court.
But as the hearing got under way, the family's barrister Grant Armstrong told the judge: "This case is now about time.
"Sadly time has run out."
Saying the case was "worthy of a Greek tragedy", Mr Armstrong said Charlie's parents had made a decision following the latest medical reports and scans.
He said damage to Charlie's muscle and tissue was irreversible.
"The parents' worst fears have been confirmed," he said
"It is now too late to treat Charlie."
Great Ormond Street Hospital said "the agony, desolation and bravery" of the decision by Charlie's parents "command GOSH's utmost respect and humble all who work there".
Mr Justice Francis paid tribute to the family and said no-one could comprehend their agony.
He also praised Great Ormond Street staff who had worked "tirelessly".
The judge said it was a "disgrace" that staff had been subjected to abuse and threats.
But outside court, supporters calling themselves Charlie's Army reacted with anger and tears, chanting "shame on you judge" and "shame on GOSH ".