A male patient has died following an ambulance fire at Naas General Hospital in Co Kildare.
The incident occurred at around 2pm at the entrance to the Accident & Emergency Department, when there was an explosion at the rear of the ambulance.
Gardaí say a male patient - aged in his 70s - was in the ambulance at the time of the fire and was pronounced dead at the scene.
Two ambulance staff also received 'minor injuries'.
One has been discharged while the second is being detained at St James’s Hospital in Dublin overnight for observation.
The Naas A&E department was temporarily closed following the 'serious incident'. It reopened this evening for both walk-in attendances and ambulance admissions.
In a statement, the hospital said it "would like to thank the public for their co-operation during the disruption to services at the hospital earlier today".
HSE chief Tony O'Brien spoke to reporters at Naas General Hospital earlier, explaining "we're currently focusing our actions on the possibility - and I stress the possibility - that this was an oxygen related incident".
Mr O’Brien also said the fire was the direct cause of the patient's death.
The vehicle itself has been described as ‘brand new’ and was manned by two experienced paramedics.
In a statement, the HSE said: "The NAS [National Ambulance Service] is issuing an immediate safety action notice to ensure all oxygen is checked and has also directed its supplier to undertake a program of checks on the oxygen in our ambulances.
"Staff have also been asked to re-familiarise themselves with the emergency ambulance evacuation procedures."
The organisation says its officials have met with the family of the deceased, and supports have been made available to them.
The HSE has also praised "the heroic efforts of our paramedic colleagues and hospital staff in attempting to save the life of the deceased".
Gardaí in Naas and the HSE are investigating all the circumstances surrounding the fire.
Ambulance at centre of Naas fire was 152-registered; two experienced paramedics; HSE examining possibility that oxygen tank blew up.
— Richard Chambers (@newschambers) September 22, 2016