Can a debt be sent to collection if we never recieved any notification of a debt?

by Malcolm
(Petaluma, California)

I received a collection notice from a debt collector for a school tuition debt owed by my stepdaughter's father. At no time did the school ever contact my wife and I to request any payment or inform us that payments were not being made by her father but the debt collector insists it is now our debt. The school sent all other communications (report cards, progress reports) to us but at no time informed us that fees were not being paid. Is it legal for them to release our name and address to a collection agency despite the fact that they confirm that the debt is owed by her father?

Thanks