It would depend on the situation. I'd want to be notified regardless, so I could make my own decision. I'd certainly rush home if it was a situation of being able to come home to say goodbye and provide comfort to my loved one in his/her final moments. If the loved one was already gone, though, I might or might not interrupt the trip to go home to mourn.
My grandmother died on the first day of our 2008 Disney trip and I didn't cut the trip short to come home for the funeral. My grandmother wouldn't have wanted that, and my mother didn't want it either (I'd have come home if she needed the support/help). My grandmother was 90, in the advanced stages of Alzheimers, and frankly we'd said our goodbyes and mourned losing her long before her physical death. A few members of the extended family got a little high and mighty about me not being there but the people who mattered - my mom, my brother, and my grandmother's sisters who we were particularly close to - all agreed that Grandma wouldn't have wanted us to cancel a trip with the kids to come to her funeral. A different set of circumstances might have warranted coming home but in this case we decided to go ahead with the trip as planned.