Sinn Féin leader Gerry Adams has highlighted a case where the two back wheels of an ambulance fell off while it was transporting a patient on a life support unit from Letterkenny, Co Donegal to University College Hospital in Galway.

The incident happened on August 26th outside Sligo and the ambulance was also carrying a nurse, an anaesthetist and two paramedics.

Mr Adams said that only for the skill of the driver the incident would have been a much more serious accident. Subsequently, the patient died, but it was not believed the accident played any part in this.

He said there was a delay of at least 30 minutes while a new ambulance was sent for.

The Sinn Féin leader said three similar incidents had happened last year and he asked what the Government had done to address the issue given the verdict of an independent assessor who said there was a design flaw in the Mercedes model of ambulance.

He said ambulance users and staff needed to be assured that this model of ambulance would be removed from service and replaced.

He said the Mercedes Sprinter 515 model was eight years old and had 411,000km on the clock, 50,000 a year.

According to an inspection report by an independent consulting engineer and assessor there was a serious design flaw in this ambulance model.

“The vehicle design has one major negative characteristic in the wheel stud nut design. This weakness in design can result in wheel stud failure if a sudden stress is transmitted to the vehicle via the wheel.”

The assessor said the wheel studs were too small in that ambulance model.

Mr Adams asked how many ambulances were of this model, the implications for this “is obvious”.

He said the independent report had been with the HSE for three weeks.

Taoiseach Enda Kenny said €144 million had been allocated to the National Ambulance Service for 2015. There is a fleet of 500 vehicles including emergency ambulances.

Mr Kenny said he had been given a preliminary report which said the ambulance broke down at Ballindine on the Mayo/Sligo border at 14.10 on August 26th. He said another ambulance arrived within five minutes and the patient arrived in ambulance at 15.05.

He stressed there was no deviation at all from the care and attention being given to the patient.

He said the ambulance service was carrying out a comprehensive investigation to determine exactly what happened and the preliminary investigation suggested the wheel nuts loosened which resulted in them being dislodged.

He said a similar incident occurred to his own car when the wheel became dislodged when “the change from wheel braces to air tightening of nuts resulted in somebody not doing a job properly”.

He said they would discover whether the wheel nuts were not tightened properly or whether they were the wrong configuration.

But Mr Adams expressed disappointment with the Taoiseach’s answer and said there had already been an independent assessment which “says very clearly that there is a weakness in design”.

“My question was what steps has the Government taken to ensure this matter was urgently dealt with. I understand some staff in the Sligo area are refusing to drive this particular model of ambulance.”

He said a similar incidence occurred in March 2014 in Co Louth and the week before there was another such incident in the Midwest and earlier that year the Government Fire Brigade’s ambulance lost its wheel.

He said the independent assessor’s report had been on the desk of the HSE for three weeks. “What has it done since then?”

The Taoiseach said Mr Adams had the final report while he had a preliminary report.

He said “the Mercedes ambulances comply fully with maintenance and service records” and he understood the independent report had been acted on.

Mr Kenny said he had information that another ambulance arrived within five minutes, but Sinn Féin’s Pádraig Mac Lochlainn said it arrived 30 minutes later.

The Taoiseach said he would have that checked.