Aaron & Nick Carter Mourn the Death of Father Robert Carter

Bob Carter, the father of Nick and Aaron Carter, has passed away, PEOPLE confirmed. The family's patriarch died at the age of 65 in Florida last night (May 16) and as of now the cause is unknown.

His sons took to social media to express both their heartache for their huge loss as well as to show love for their dad. “I am heartbroken to share the news that our father, Robert, passed away last night…,” Nick tweeted this afternoon. “While we learn more about the cause of death, and begin the grieving process, we ask that our privacy be respected at this difficult time.”