21‭ ‬January 1919: Dan Breen and Sean Treacy carried out an ambush on an RIC escort at Soloheadbeag, Co. Tipperary. They were members of the South Tipperary Brigade of the Irish Volunteers (IRA). The cart the RIC were escorting was carrying gelignite for a quarry in the Soloheadbeag area (about four miles from Tipperary Town and about one mile from Limerick Junction).  In the ambush, the two RIC men, guarding the consignment, Constables James McDonnell and Patrick O'Connell, were shot dead. It was the start of the Irish War for Independence.

We expected there would be an escort of about six armed police and vie had the full intention
not alone of taking the gelignite they were escorting but also of shooting down the escort, as an assertion of the national right to deny the free passage of an armed enemy.
The moral aspect of such a decision has been talked about since and we have been branded as murderers, both by the enemy and even by some of our own people, but I want it to be understood that the pros and cons were thoroughly weighed up in discussion between Treacy and myself and, to put it in a nutshell, we felt that we were merely continuing the active war for the establishment of an Irish Republic that had begun on Easter Monday 1916. 
DAN BREEN
http://www.bureauofmilitaryhistory.ie/reels/bmh/BMH.WS1739.pdf