June 1917 brought a severe personal blow to Redmond when his brother Willie died in action on the front at the onset of the Battle of Messines offensive in Flanders; his vacant seat in East Clare was then won in July by Éamon de Valera, the most senior surviving commandant of the Easter insurgents. It was one of three by-election gains by Sinn Féin, the small separatist party that had played no part in the Rising, but was wrongly blamed by Britain and the Irish media. It was then taken over by surviving Rising leaders, under de Valera and the IRB. Just at this time Redmond made a desperate effort to broker a new compromise with Irish unionists, when he accepted Lloyd George's proposal for a national convention to resolve the problem of Home Rule and draft a constitution for Ireland. An "Irish Convention" of around one hundred delegates sat from July and ended in March 1918. Up until December 1917 Redmond used his influence to have a plan which had been put forward by the Southern Unionist leader Lord Midleton, accepted. It foresaw All-Ireland Home Rule with partial fiscal autonomy (until after the war, without customs and excise). All sides, including most Ulster delegates, wavered towards favouring agreement. Already ailing while attending the Convention, his health permanently affected by an accident in 1912, Redmond also suffered assault on the street in Dublin by a crowd of young Sinn Féin supporters on his way to the Convention, which included C.S. 'Todd' Andrews. On 15 January, just when he intended to move a motion on his proposal to have the Midleton plan agreed, some nationalist colleagues—the prominent Catholic Bishop O'Donnell and MP Joseph Devlin—expressed doubts. Rather than split the nationalist side, he withdrew his motion. A vital chance was lost. He ended his participation by saying that under the circumstances he felt he could be of no further use to the Convention in the matter. His final word in the Convention was the tragic one – "Better for us never to have met than to have met and failed." Late in February the malady from which he was suffering grew worse. He left Dublin for London knowing that a settlement from the Convention was impossible. An operation in March 1918 to remove an intestinal obstruction appeared to progress well at first, but then he suffered heart failure. He died a few hours later at a London nursing home on 6 March 1918. One of the last things he said to the Jesuit Father who was with him to the end, was, "Father, I am a broken hearted man."