But it is only now that his father, Gary Sinise, is opening up in detail about his son’s final days. In an interview with ET, Gary shares how his son gracefully navigated through the last difficult moments of his life.

To start with, Gary revealed that his son actually completed a music album he had been working on for the past few years. “I bought him his first drum set when he was 9 years old,” Gary recalled in a conversation with ET.

Talented musician

”He played through high school, and then he went to USC Thornton School of Music. He was playing drums all through college and studying songwriting and composition. He created a bunch of pieces of music while he was at college.”

But during the last years of his life, Mac just put them away and didn’t do anything with them. In January 2023, he said, ”Dad, I think I want to try to finish this music that I worked on all those years ago in college.”

Just like his father, Mac was a very skilled and talented musician. He learned to play the harmonica while undergoing cancer treatment. Mac recorded the final parts of his album during his last week in life, and his album is currently being finalized. It will be available for purchase on the Gary Sinise Foundation website. Additionally, it will be streamable for those who wish to listen to it.

Last days of his life

Gary reminisces about the day when Mac had a viewing party. Sadly, it would become a kind of farewell.

”It was a joyful day. The following night, I went on television and talked about Mac. Then the next day, I had to call the ambulance and take him to the hospital,” Gary shares.

But Mac needing to go to the hospital was quite common. He would often spend a few days there, stabilize, and then be able to come home. The family thought that would be the case on this day as well – but they were mistaken. At the hospital, doctors realized the situation was extremely serious, and soon it dawned on the Sinise family that Mac was probably in his last days of life.

Many might think that everything was pitch black in this situation – but Gary points out that Mac found peace in knowing he had done everything he wanted in life.

Sure, there were dark moments, but Mac was a true fighter all the way.

”He was at peace. He was happy at the end of his life. He was joyful… He was smiling,” Gary says.

Forrest Gump story on death bed

In the interview with ET, Gary also revealed a wonderful, heartwarming story about his son. Gary was present during Mac’s last hours of life, but sometimes he needed to take a break and leave his son’s hospital bed.

It was during one of these moments that this little story unfolded.

”I was staying with him at the hospital at the end… I had to step out for something at one point, and I stopped by the nurse’s station on the way in. I said, ‘How’s Mac doing? What’s he’s doing?’ [The nurse said], ‘He’s watching “Forrest Gump” on his phone.’ He was in there watching ‘Forrest Gump.’ It made him feel good. I think it made him feel closer to me sometimes. He would watch it when I was gone,” Gary shared.

Tried 25 different drugs

Gary Sinise, father of three children, shared his son’s rare cancer diagnosis in August 2018.

Mac had started to experience notable pain in his tailbone.At first, he ignored the pain, but eventually he felt compelled to see a doctor. Unfortunately, a massive tumor was discovered on his sacrum, a bone in the lower back. Doctors managed to remove the tumor, but the cancer returned in 2019. The situation worsened, and Mac experienced severe pain during certain periods.

”It was not going to get better. There’s no cure,” Gary shared and added:

”We tried 25 different drugs. These are just drugs that are used on other cancers and the doctors kept trying and they said, ‘As long as you want to keep trying, Mac, we’ll keep trying. We’ll come up with something.’ Mac said, ‘I want to keep trying.’ He was an incredible fighter.”

Eventually, Mac became paralyzed by his illness. He stopped feeling anything from his chest downwards and was unable to walk.

”It’s just the nature of this awful cancer. He was fighting and I wasn’t going to stop fighting for him. I never wanted to think that we were going to lose the battle even though you know that you’re fighting uphill all the way.”

Gary Sinise has repeatedly shared his son’s story, hoping to raise awareness of this terrible form of cancer. Sharing Mac’s story is also a way to keep his memory alive – he was not just a cancer patient but also an incredible and inspiring individual, it seems.

No one should have to pass away at the age of 33, and Gary still finds it hard to believe that his son is no longer by his side.

”It’s hard to even think like that, because somehow it feels like he’s just on vacation, he’s gonna come back.”