Venice, November 21 - Thousands of Venetians crossed a pontoon bridge on the Grand Canal in a pilgrimage to the Madonna della Salute church Wednesday in an annual celebration of the end of the plague that devastated the lagoon city in 1630. Construction on the church, the name of which translates to Our Lady of Health, began in 1631 by Baroque architect Baldassare Longhena as a votive offering from the city to deliver it from pestilence, which had killed one third of the population in the course of a year. In a token of thanks, it was also decreed that the Senate make pilgrimage to the church each year on November 21, the Feast of the Presentation of the Virgin, by crossing the Grand Canal on a temporary pontoon bridge. The day is known as the Festa della Salute, or the Feast of Good Health. "Here we express the faith of the Christian people who welcome, thanks to Her close bond with Christ, the centrality of Mary, the very mother of our saviour," said Venice Patriarch Francesco Moraglia in a mass Wednesday.