Fuair siad bás ar son Saoirse na hÉireann.

McDonnell was born on Slate Street in the Falls Road of west Belfast on 14 Sept 1951, and was the fifth of 10 children and went to a nearby Roman Catholic school.

McDonnell was arrested in Operation Demetrius and interned on the prison ship HMS Maidstone. He was later moved to Long Kesh Prison for several months. Upon release he joined the Provisional IRA Belfast Brigade. McDonnell met Bobby Sands in the run up to an IRA firebomb attack on the Balmoral Furnishing Company. During the ensuing shoot-out between the IRA and the RUC and British Army, both men along with Séamas Finucane and Seán Lavery were arrested. McDonnell and the other men were sentenced to 14 years in prison for possession of a firearm. None of the men accepted the jurisdiction of the court.

McDonnell agreed with the goals of the 1981 Irish hunger strike: the right not to wear a prison uniform; the right not to do prison work; the right of free association with other prisoners; the right to organise their own educational and recreational facilities and the right to one visit, one letter and one parcel per week.

He went 61 days without food before dying on 8 July 1981. He had two children. His wife Goretti took an active part in the campaign in support of the hunger strikers.

McDonnell was buried in the grave next to Bobby Sands at Milltown Cemetery. John Joe McGirl, McDonnell’s election agent in Sligo-Leitrim, gave the oration at his funeral. Quoting Pádraig Pearse, he stated, “He may seem the fool who has given his all, by the wise men of the world; but it was the apparent fools who changed the course of Irish history”.