Scoop's tour manager broke the sad news when he said of the Grammy-winner, "I am honestly lost for words… You took me all over the world and had me performing alongside you on some of the biggest and greatest stages on this planet, the things you taught me have truely made me the man I am today. Thank you so much, I love you x."

Reminisce Festival, where Fatman Scoop was set to perform Sept. 7 also posted to Instagram saying, "It is with the deepest sorrow that we at Reminisce have received the devastating news of the tragic passing of the legendary Isaac Freeman III, known to us all as Fatman Scoop. This loss has left us all heartbroken."

Not long after, his family also released a statement, which said in part ... "He was the laughter in ours lives, a constant source of support, unwavering strength and courage."

TMZ broke the news that the legendary hip hop hype man was performing at Town Center Park in Hamden, CT when he appeared to suffer a medical emergency.

Horrifying video showed Scoop collapse mid-performance.

The icon worked with a ton of big names in hip hop over the years ... collabing with the likes of Missy Elliott, Mariah Carey and Jermaine Dupri ... just to name a few.

Following his collapse and being rushed to the hospital, Hamden Mayor Lauren Garrett asked fans to "please keep him in your thoughts and prayers."

We are out to Scoop's agent for more information ... so far, no word back.

He was 53.