A hospital has apologised after a six-month-old boy died due to "serious failings".
Harris James was mistakenly treated for pneumonia when he had a heart condition, and did not see a senior doctor in time, despite multiple opportunities to save him.
The Parliamentary and Health Service Ombudsman has ruled there were serious failings at James Paget University Hospitals NHS Foundation Trust in Gorleston and has ordered the trust pay the baby's mother £15,000.
The ombudsman's report found mistakes were made in Harris's care and that the trust mishandled his mother's complaint, while also failing to properly investigate the death.
WATCH: Health Ombudsman Rob Behrens said the case would "make any decent person angry".
Mr Behrens added: "This tragic case shows how important it is that people speak up when mistakes are made. It is crucial that the trust learns from its failures to make sure they are not repeated."
Baby Harris was admitted to the trust on November 2, 2015, after being referred by his GP.
Harris had experienced weight loss following gastroenteritis and the GP notes, which were submitted to hospital, said the area of his stomach just below his ribs was drawn inwards.
However, this fact was not recorded in his medical records at the hospital.
Harris underwent blood and urine tests and an appointment was made with a dietitian for four weeks later.
But on November 12, he was taken by an ambulance to the trust's A&E department after he vomited and became floppy.
Harris was found to have a fast heart rate and was breathing very fast. A chest X-ray showed that his right lung had changed and part of his left lung had filled with fluid.
Staff suspected he had sepsis and possibly aspiration pneumonia, which occurs when food or liquid is breathed into the lungs or airways.
Harris was given oxygen, antibiotics and fluids, and was transferred to a paediatric ward but his condition got worse.
An electrocardiogram (ECG) showed several heart abnormalities, including a fast heart rate, but Harris was still not referred to a specialist.
Despite clear signs he was getting worse, Harris was not seen by a consultant until the following morning.
Soon after that, he suffered a cardiac arrest and died.
A post-mortem examination showed Harris had a heart abnormality which had caused damage to his heart.
His mother complained about his care to the trust but bosses failed to acknowledge the mistakes.
In a statement, Harris' parents, Mary and Ryan, said: "Our son was an affectionate and sweet little boy whose sudden death devastated our family. We won't ever be able to forgive James Paget Hospital for its failings, nor will we forget the additional pain caused by its mishandling of our complaint."
The ombudsman's report concluded the trust had failed to act on the results of the ECG and chest X-ray, failed to consider Harris's history and symptoms, failed to ask for input from specialist staff and failed to escalate his care when his condition was getting worse.
"If these failings had not occurred, it is likely that the trust would have recognised that (Harris) had a problem with his heart," it said. "In these circumstances, he would have received the correct treatment instead of being treated for suspected pneumonia."
Anna Hills, chief executive at James Paget University Hospitals NHS Foundation Trust, said: "We have apologised to Harris's family for the failings in his clinical care - and for the manner in which we communicated with them and handled their complaint when they raised concerns after his death.
"We have now implemented changes to ensure that, in the future, action is taken to ensure appropriate clinical escalation in similar situations and also that bereaved parents and relatives are treated with the compassion, sensitivity and respect they deserve."
The Ombudsman's report was released on the same day as the Trust's latest Care Quality Commission (CQC) inspection.
The hospital kept its 'good' overall rating, and the responsiveness of its services were rated 'outstanding'.
The inspection took place in September and October this year, although CQC officers did find that the safety of services required improvement.