A mother-of-two who broke her leg running a half marathon was wrongly diagnosed and died after doctors' "gross failings", a coroner has ruled.
Sarah-Jayne Roche, 39, pulled out of the 2018 Cardiff Half Marathon with what was diagnosed as a hamstring injury - but she had fractured a femur.
Mrs Roche, of Rhondda Cynon Taff, went to hospital three times before surgery.
She had a cardiac arrest during surgery 12 days after the race and died because of neglect, coroner Graeme Hughes said.
Mr Hughes said there was "a failure to provide basic medical attention" for Mrs Roche and delivered a narrative conclusion.
He added: "There have been gross failings by clinicians to diagnose the fracture and that contributed to the development of deep vein thrombosis which was responsible for pulmonary thromboembolism that led to cardiac arrest."
Mr Kamal Asaad, medical director at Cwm Taf Morgannwg University Health Board, apologised to Mrs Roche's family and friends for the failings in her care.
"Words are of little comfort at this distressing time but we would like to assure the family that changes have already been made to help prevent such failures in the system from happening in the future," he said.
"A full investigation into the care she received was instigated immediately, and actions are being taken and closely monitored to address the shortcomings that were identified. These include strengthening our clinical processes, including X-ray procedures in A&E as well as our protocols for more detailed assessments and investigations before reaching a definitive diagnosis.
"We accept the coroner's ruling and will now review all of his findings to ensure we fully address all of the failings."
Pontypridd Coroners' Court heard Mrs Roche, of Beddau, entered the race with her husband Steven to raise money for Parkinson's disease research after her father was diagnosed with the illness.
Seven miles into the run on 7 October Mrs Roche, who had two sons aged 12 and eight, felt a "shooting pain up her leg" and pulled out of the race.
St John Ambulance volunteers diagnosed a pulled hamstring but she went to the Royal Glamorgan Hospital in Llantrisant because of the pain.
Mr Roche told the inquest his wife was "in a wheelchair in very considerable pain" and was advised to "rest up and take paracetamol and ibuprofen".
"There was no discussion about an X-ray, their conclusion was there was not much else to do. They believed it was a hamstring injury," he said.
Ms Roche, a learning support assistant at Treorchy Comprehensive in Rhondda, was admitted to the same hospital by ambulance a week later in "absolute agony".
She died of cardiac arrest during an operation to pin her broken thigh bone on 19 October.
Mr Hughes said: "Simple checks of procuring an X-ray on three opportunities did not happen.
"There was serious underestimations of Mrs Roche's condition. A simple X-ray could have detected it.
"The fact Mrs Roche was unable to bear weight on the leg and was in excruciating pain on each visit to the hospital. I believe there were three red flag opportunities to procure an X-ray."