On that date , an ambush party of IRA volunteers including Dan Breen and Seán Treacy , attacked a pair of Royal Irish Constabulary ( RIC ) men who were escorting a consignment of gelignite to a quarry in Soloheadbeg , County Tipperary .
They were escorting a shipment of gelignite to a quarry in Soloheadbeg , County Tipperary .