On May 18, 1765, the General Hospital and much of Ville-Marie fell prey to fire. The walls of the hospital remained standing but the interior had to be completely rebuilt. Its residents (18 sisters, 17 lady boarders, 63 poor people and 16 illegitimate children) were left homeless. The group was housed at the Hôtel-Dieu during the reconstruction.
An outpouring of generosity from the Native American, Montreal and London communities enabled the Grey Nuns to rebuild the hospital and continue their work. The Annals of the Institute bear witness to this:
‘Madame d’Youville, powerful by her industry and that of her Daughters, found by many springs of Providence, the means to rebuild the house. The public lent a lot to help re-establish the Hospital. The American Indians provided something: knowledge, those of the Sault Saint Louis, in money 82 pounds and in effects, cloth, cotton, spoons: 19 pounds 6 cents; those of the Lake of the Two Mountains: in money, 108 pounds, they sent moreover pins, porcelain beads, belts, mittens, shoes made from deer skin, sugar, covers, knives, etc. for the value of 252 pounds and 2 cents, which makes in all the sum of 360 pounds and 2 cents, provided by the latter. Various people gave 5 296 pounds and 11 cents. The collection made in this city by Mr. Poudret gave 300 pounds. The association of Bonne Mort gave 160 pounds. The collections made in London, England gave them nineteen thousand four hundred and seven pounds. The workers had obtained permission to work on the building on Sundays, which they did between services. The work progressed so rapidly that a part of the house was ready to receive them at the beginning of December, but the project was not completed until 1767. To rebuild the church, the hospital and the house of the recruits, the expense amounted to 24 651 pounds and 9 cents. In addition, they were obliged to buy cloth, gauze, etc. to dress themselves, mattresses, bunks, covers, canvas, etc. for 2000 pounds. Finally, in addition to the above-mentioned expenses, for the repairs of the buildings, the other expenses of the house amounted for the year 1765 to 23,140 pounds and 14 cents.
ASGM, Old Journal, Vol. I, p. 62-64