Stolen passports

Good Day I have 2 wonderful tenants and our property was broken into and there passports were stolen. I need to know if anyone knows what we can do to get there passports. Do we have to apply for a new passports.

The first thing is to contact the nearest embassy or their issuing agency to get the passports cancelled. A real passport is very valuable to a wide variety of people but a cancelled passport is a red light to the airport security and immediate arrest.
You might well stop a terrorist or drug trafficker.

After that the procedure varies depending upon the country your guests are from.
If it's the UK, I can advise.