How do you track down a person when their name has changed?

Recently my Uncle has passed and he had 2 Kids - The mother had left my uncle with the kids (when the kids were small) and no one had seen hide nor hair from any of them since. My question is this... How can I find out where the kids are to let them know that their father has passed on?

The mother most likely had remarried and changed their last name. -

Is their a way to do this on the internet that will not cost any money?

I've tried the free people searches - but they are garbage - do you know of a site where they may list family history or some way to track name changes?

Thanks to all who answer

How do you track down a person when their name has changed?

sorry to say man, but i don't think there's any way one can track all the ppl who're changing their names....., if your aunt is re-married to someone, she might have registered her marriage with the old name...., you can find her out by that way - but again, i don't think she has registered her marriage online..... : (

you put some blog or forum or something - online to find out your cousins.......

wish you all the best