An IRA flying column, commanded by Michael Kilroy, ambushed a mobile patrol of the Royal Irish Constabulary including Black and Tans recruits at Carrowkennedy, near Westport, County Mayo.

On Thursday 2 June, the West Mayo flying column was based in the townland of Claddy, near the road from Westport to Leenaun.

[1] In the mid-afternoon, O/C Michael Kilroy was informed that an RIC patrol including two Crossley Tender lorries and a Ford car had stopped at the rural area of Carrowkennedy.

[6] A local mechanic/electrician called Gus Delahunt was pressed into service by District Inspector Stevenson to drive the Ford car as a police driver was unwell.

[2][1] The RIC were apparently not aware that Delahunt had previously helped the IRA by servicing commandeered vehicles and raiding for petrol.

[1] The IRA Active Service Unit saw the convoy through binoculars from Claddy and made their way secretly to the main road.

Kilroy knew that the patrol would have to return the same way as the IRA had destroyed Glenacolly Bridge in Erriff, four miles further towards Leenaun.

[1] [2] The approximately 35 well armed IRA volunteers were divided into three sections and subdivided into small units of six men under the command of a more experienced officer.

These included Commander Joe Doherty, Captain Jim Moran and Rick Walsh They were positioned further west, from the end of the first section's position along a wood to the main road, at an old burned-out police hut, which was used in the Land War to keep the Widow Salmon, who still lived Fifty yards to the rear , in order.

[1] The Ford Car had broken down at about the same time, Delahunt had made repairs and was bringingup the rear which he later felt had saved his life.

[1] Jimmy O'Flaherty, a former Connaught Ranger, lined up his rifle sights on DI Stevenson in the lead vehicle, killing him with a shot to the head.

[5] A second gunner fired a burst from the Lewis in the direction of the third section, then he swung the muzzle in the air to protect himself from the riflemen above.

[1] Four men in the lorry were now dead: DI Stevenson and Constables Sydney Blythe, James Brown and John Doherty.

Michael Kilroy was worried that if the first lorry did not surrender soon, the column might not have time to concentrate on the RIC men in the cottage.

A fresh assault on the lorry was made by IRA volunteers Johnny Duffy and Tommy Heavey, who had bayonets.

[1][5] A rifle grenade which was being hurled by the RIC fell back into the lorry and exploded, killing the man who threw it and fatally wounding others beside him.

[5] Being both Irish policemen the householder prepared a drink for Creegan and the other wounded constable Cullen who remained outside as it was warm.

[5] With the captured Lewis gun, IRA volunteer O'Flaherty then fired on the occupied cottage from a covered position.