Terminally-ill British toddler Alfie Evans died on Saturday after doctors withdrew life support, following a long legal battle and a campaign by the parents that drew support from Pope Francis.
"Our baby grew his wings tonight at 2:30am (0130 GMT). We are heartbroken. Thank you everyone for all your support," the mother, Kate James, wrote on Facebook.
The parents had fought to take their son, who had a degenerative condition that caused irreversible brain damage, out of a hospital in Liverpool in northwest England to a clinic in Rome but lost a final court appeal on Wednesday.
Doctors had already removed life support on Monday after the parents lost a previous appeal to keep him alive despite doctors' recommendations.
- 'A devastating journey' -
Alder Hey Children's hospital, where the 23-month-old was being treated, expressed their condolences.
"All of us feel deeply for Alfie, Kate, Tom and his whole family and our thoughts are with them.
"This has been a devastating journey for them," the hospital said.
Pope Francis tweeted he was "deeply moved" to learn Alfie had died.
"I am deeply moved by the death of little Alfie. Today I pray especially for his parents, as God the Father receives him in his tender embrace," wrote the pontiff, who met the child's father Thomas Evans in the Vatican last week.
Supporters began to leave floral tributes outside the hospital and a post on the "Alfie's Army" Facebook page, which has 801,000 members, said balloons would be released from a park near the facility later on Saturday.
Evans was born on May 9, 2016 and was first taken to hospital in December of that year after suffering seizures.
His condition worsened and, a year later, in December 2017, the hospital recommended withdrawing life support.
The parents disagreed and the two sides went to court.
At a hearing in February the hospital's lawyers argued that Evans had suffered "catastrophic degradation of his brain tissue" and said Italian doctors who visited the child were agreed on the "futility" of trying to find a cure.
Helen Cross, an expert in child epilepsy at another children's hospital in London, told the hearing that scans showed over 70 percent of the baby's brain fibre had been lost and said there was "no prospect of recovery".
- 'Save our son' -
Pope Francis intervened several times in a case that touched hearts around the world and prompted vigils in Italy and Poland.
Earlier this week the pontiff wrote on Twitter that he hoped the parents' "desire to seek new forms of treatment may be granted".
"The only master of life, from the beginning to its natural end, is God, and our duty is to do everything to protect life," he said.
Thomas Evans had also met with the pope in the Vatican last week and asked him to "save our son".
Italy granted citizenship to the toddler on Monday in the hope of facilitating his transfer to the Bambino Gesu (Baby Jesus) paediatric hospital in Rome.
After losing his legal battle, the father on Thursday had asked supporters, who have staged angry vigils outside the hospital where the baby was being treated, to go home.
Medical staff have been subjected to severe online abuse and police officers had to be deployed outside the clinic on Monday after some protesters tried to gain entry.
- Ethical battles -
The case is the latest in a series of high-profile battles between parents of seriously ill children and the British authorities.
British law states that parents "cannot demand a particular treatment to be continued where the burdens of the treatment clearly outweigh the benefits for the child".
If agreement cannot be reached between the parents and the healthcare professionals, "a court should be asked to make a declaration about whether the provision of life-sustaining treatment would benefit the child".
The most recent example was that of Charlie Gard, who was born in August 2016 with a rare form of mitochondrial disease.
He died last year, one week short of his first birthday, after doctors withdrew life support treatment.
Gard's parents fought a five-month legal battle for him to be taken to the United States for experimental treatment.
The parents of Ashya King defied professionals in 2014 when they snatched their cancer-stricken son from a British hospital and took him to Prague for proton beam therapy.
King, now eight years old, has since been declared clear of the disease.
Alfie's parents had fought to take him from a hospital in Liverpool to a clinic in Rome
Pope Francis intervened several times in a case that attracted worldwide attention
Tom Evans had asked supporters, who have staged a series of vigils outside the hospital, to go home