"The same thing has already happened to ten families."
Translation:Stejná věc už se stala deseti rodinám.
You can definitely use it in the typical second position as well: "Stejná věc se už stala deseti rodinám." is perfectly OK.
Why is the above also OK? There are some exceptions to any rule. Sometimes it is possible to change the order somewhat, the už here is unstressed as well. It will be pretty hard to find some scientific description of this exact type of sentence and it will be in Czech for sure. There are whole university theses about clitics https://theses.cz/id/3hw0hg/Diplomov_prce_Veronika_Novkov_2012.pdf
No jo... Muj uraven cestiny jeste neni tak dobré xD. Nemuzu uz to precist. Ale, jestli najdes neco ze, neni velmi tezky... Prosim, mohl/a bys to sdílat? :)
Ale just in case ;). For now, I will just take in count that "uz" CAN BE an exception SOMETIMES and I DONT KNOW when but I TRUST ;).