Robert ‘Bob’ Carter, father of singers Nick Carter and Aaron Carter, died at the age of 65 on Tuesday night. Both Nick and Aaron shared the news on social media on Wednesday. The cause of death has not been determined.

“I am heartbroken to share the news that our father, Robert, passed away last night,” Nick, 37, said in one tweet.

“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,” read another.

Aaron tweeted out a tribute to his father as well.

“My heart is Completly (sic) shattered I’m in shock and I loved my dad so much,” Aaron, 29, tweeted on Wednesday. “#RIPDADDY I love you. This is the last pic I have my dad.” The final picture shows Aaron taking a selfie with his father.

He also posted a picture of him and his dad on Instagram captioned, “My heart is broken, We are so hurt we lost you poppa way too soon. You were never human to me, you were always my real life super hero.”

Bob Carter passed away in Florida, where he lived.

It is the second stunning death in the Carter family in recent years – Leslie Carter, sister to Nick and Aaron, died at age 25 due to a drug overdose.