A jury at the circuit court in Limerick has been told that a 20-year-old man was driving his car at such speed that he failed to stop, and struck a Garda and a fireman propelling them into the air killing them.

Details of the deaths of Garda Brian Kelleher and fireman Michael Liston were given at the opening of the trial of Niall Shannon, of Ballylongford in Co Kerry, who denies casuing their deaths in a car accident in Limerick last year.

Mr Shannon is pleading not guilty to a charge of dangerous driving causing the deaths outside Foynes on 25 February last year.

He also denies a charge of driving with excess alcohol, and driving a car with two worn front tyres on the same date.

Outlining the case to the jury this afternoon, prosecuting counsel John O'Kelly said the charges arise from a tragic accident which happened shortly after five am that morning.

In the accident, he said, a car driven by Mr Shannon came upon the scene of another crash and knocked down and killed the two officers.

Because of the earlier accident there were flashing lights on the road in addition to a fireman using a flashing stick to warn oncoming motorists.

He said the car driven by Mr Shannon drove right past the warning fireman into the scene of the other accident where Garda Kelleher and Mr Liston were working.

His car hit the open door of a fire truck and then struck the Garda and the fireman, throwing them up in the air.

Mr O'Kelly said for somebody to drive in such a manner that he failed to stop, not just when there were flashing lights on the road, but also when there was a uniformed fireman trying to flag him down is evidence of the most dangerous driving you could possibly conceive.

He said Mr Shannon was driving his car at a speed so fast it propelled the two victims into the air, one into a wall and the other 30m down the road.

He said in addition there will be evidence of driving with excess alcohol and the jury may also consider this when deciding on the charge of dangerous driving.

The trial before a jury of seven women and five men before Judge Carol Moran is likely to take a week.