Construction Work by Workers When the Contractor is Sitting Shiva

A contractor building a building in a Jewish neighborhood is sitting shiva. Can the workers continue their work during his mourning days?

Workers are prohibited from continuing their work, even on a contract basis, and certainly not on a daily or hourly wage, until after the shiva, due to appearances.

Shulchan Aruch, Yoreh De'ah, Laws of Mourning, Siman 380, סעיף 19: "If he has a building in the hands of others, on a contract basis, during weekdays or Chol HaMoed, it should not be done, even if it is outside the city limits; and if these contractors are non-Jews, they are permitted to build on Shabbat and Yom Tov that fall during the days of mourning, if it is outside the city limits and there is no other city with Jews within the vicinity of that house."
And the Shach wrote, Yoreh De'ah, Siman 380, סעיף קטן 21: "And even if he handed it over to them before the mourning or before Chol HaMoed, it is prohibited due to appearances, as people may come there and see the work and say: 'Look, he handed over his work to others during the days of mourning or Chol HaMoed' and they do not know that it was handed over to them beforehand."