McCanna Anthony “Mac” Sinise, a musician and son of actor Gary Sinise, died on Jan. 5 following a battle with a rare spinal cancer called Chordoma. He was 33.

The CSI: NY actor shared the news of his son’s death on his Instagram and his foundation’s website Tuesday, where he wrote a heartfelt tribute.

“The week the album [Resurrection & Revival] went to press, Mac lost his battle with cancer,” Gary wrote. “He died on January 5, 2024 at 3:25pm, and was laid to rest on January 23rd. Like any family experiencing such a loss, we are heartbroken and have been managing as best we can. As parents, it is so difficult losing a child. My heart goes out to all who have suffered a similar loss, and to anyone who has lost a loved one. We’ve all experienced it in some way. … I am so blessed, fortunate, and proud to be his dad.