Ireton fell ill of the plague that was raging through the town, and died on 26 November. His loss reportedly "struck a great sadness into Cromwell" and he was considered a great loss to the administration. There are various anecdotes about his demise from Irish ecclesiastical and English royalist sources. Thus, his death has been depicted as divine punishment for the execution of Bishop O'Brien, who prior to his death had called upon Ireton to answer at God's judgment seat for his murders; the Hibernica Dominicana claims that on his death bed, Ireton was "privately muttering to himself 'I never gave the aid of my counsel towards the murder of that bishop; never, never; it was the council of war did it… I wish I had never seen this popish bishop'." Philip Warwick stated that among Ireton's last words were "blood! blood! I must have more blood!".