The Venetian government was at a complete loss to stop the outbreak. In a last ditch effort, the Republic passed legislation making a religious vow to Christ the Redeemer Himself (or the Redentore in Italian) asking him to take pity on Venice and stop the plague, for which the city would gratefully build a church in His honor, and forever commemorate His intervention each year with a religious holiday, processions, and other festivities on every third Sunday of July. When the plague ended, the Venetians were as good as their word, and built the Church of the Redentore on the island of the Giudecca, which you can even virtually tour here.
And the celebration still happens to this very day! It is one of the few festivities that Venetians still feel passionately about (unlike Carnival, for example, which most Venetians refuse to celebrate, and is now almost entirely for the tourists' benefit!)
This is the week that Venetians have been waiting all year for...
It's the Festa del Redentore!!
(More updates from the field as the week continues...)