Welcome to FT.

Do realize the US Government is currently shutdown due to a budget impasse. That includes the State Department and Embassies. While I have never dealt with such a situation, my guess is that your parents will not be traveling tomorrow because the airline is not going to even let them on the plane without a valid visa. The airline has no way to validate anything other than what is in a passport. My suggestion is that you call the airline and prepare to have the trip postponed. In the mean time I would suggest someone at home try to locate the passports and overnight ship them.