Doctors' failure to give antibiotics to a three-month-old boy who died of sepsis "significantly contributed" to his death, an inquest has found.
Lewys Crawford, from Cardiff, died of meningococcal septicaemia at the University Hospital of Wales in 2019.
There was a seven-hour delay between his admission to hospital and him being given antibiotics.
The inquest found there were "multiple missed opportunities" in his care and the health board has apologised.
A jury, at the hearing in Pontypridd, found Lewys died as a result of "natural causes contributed to by neglect" at the Cardiff hospital and there were "gross failures" in his care.
Speaking outside the court, Lewys's parents said the whole process had been "horrific" and doctors could have saved their son's life if he had been given antibiotics in time.
"This process has been about getting justice for Lewys and thankfully measures have been put in place at the health board to ensure what happened to Lewys isn't repeated under any circumstances," his father Aidan Crawford said.
"We want to ensure that lessons have been learnt and that no other family has to go through what we went through with Lewys.
"Lewys will be forever missed and loved dearly by us and all the family. We will all cherish our memories of the short time we had with him".
When he was admitted in March 2019, nurses immediately suspected Lewys had sepsis but doctors did not, the inquest had heard.
He should have been given antibiotics within an hour of being seen, but it took about seven hours for him to receive the drugs, after being initially wrongly diagnosed with a viral illness.
Lewys was finally diagnosed with sepsis about eight hours after he arrived at hospital just after 20:00 GMT.
The inquest heard there were several missed opportunities to administer life-saving antibiotics.
Expert witness Prof Parviz Habibi told the jury that, on the balance of probabilities, if Lewys had been given antibiotics within the first three-and-a-half hours of his admission, he would have survived.
On Thursday, Jennifer Evans, a consultant paediatrician who investigated Lewys' death, apologised to his parents.
There were 20 patients in paediatric A&E at the time, and two children were "more unwell" than him, the hearing had been told.
The jury spokesman said there was "a failure to treat Lewys with antibiotics", and this "significantly contributed to Lewys' death".
He said there was a "gross failure up to and including 23:30 on 21 March".
Coroner Graeme Hughes told the inquest there were "no systemic failures" at the hospital based on the evidence.
Ruth Walker, executive nurse director at Cardiff and Vale University Health Board, apologised for the "failings in the treatment and care we provided to Lewys".
"This is an extremely tragic case and everyone at the health board extends their sincere and heartfelt sympathies to his family," she said.
Ms Walker said action was already being taken to address some of the improvements identified in an internal investigation carried out following Lewys's death.
"We would like to reassure his family that we will do all we can to make sure that the necessary improvements are undertaken," she added.
"This will help ensure that the right treatment pathways are in place, and followed, for all patients that come into our care that we suspect may have sepsis."