Smith says in a statement (via E! Online):
Chris Kelly was my Best Friend. He was like a brother. I love him and will miss him dearly.
Our friendship began as little boys in first grade. We grew up together. It was a blessing to achieve the success, travel the world and entertain Kris Kross fans all around the world with my best friend. It is what we wanted to do and what brought us happiness. I will always cherish the memories of the C-Connection.
KRIS KROSS FOREVER, the ‘MAC DADDY’ and ‘DADDY MAC.’
The cause of death for Kelly has not yet been determined. An autopsy is scheduled for this week.