Fans were crushed on May 9 when they discovered that MTV reality TV star Chris “Big Black” Boykin had died at the early age of 45. Now the cause of his death has been revealed and it makes his passing all the more tragic. Rob Dyrdek’s Rob & Big co-star died of a heart attack, a rep for the star told PEOPLE. That news couldn’t be sadder.

The news of his death quickly shook the internet as fans and friends all mourned the loss of the former security guard turned celebrity. But the saddest reaction was definitely from Big’s former best friend Rob. Though the two had a falling out before their show ended, it is clear he was truly wrecked by his old buddy’s death.

Click here to see pics of Christopher ‘Big Black’ Boykin

“My heart is broken,” the pro skateboarder wrote in a series of posts on Twitter. “I don’t want write this post. I don’t want to believe that this is reality. I am so thankful for you. We truly were brothers that lived an unexpected unforgettable adventure. I just can’t fathom that it would end so suddenly. You will forever be in my heart.”

The reality TV star served in the U.S. Navy and worked as a security guard before making it big. He was hired by Rob to act as his body guard, but the two became close and Rob pitched their friendship to MTV as his idea for a reality series. Rob & Big ran from 2006 to 2008.

Big is survived by his 9-year-old daughter. Our hearts go out to her and the rest of Big’s family and friends.

HollywoodLifers, what do you think of Chris’ shocking cause of death? Did it surprise you? Give us all your thoughts below!

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