Lil Baby Fans Destroy Festival Grounds After Rapper Cancels Set

Lil Baby caused a riot during Vancouver's Breakout Festival which isn't unusual as festivals go, except for the fact the headlining rapper was nowhere to be found onstage ... or anywhere at the venue!!!

Video shows fans utterly destroying sections of the PNE Amphitheater on Sunday after learning Baby had canceled his set last minute.

The scene began to resemble a war zone in some places ... with angry fans lighting tents on fire while others toppled food stands and garbage dumpsters.

At one point, the mob even infiltrated a tent, leaving no TV monitor standing ... with no regard for the shattered glass that was flung everywhere.

Baby was the top act for Sunday's show ... with fellow rappers Polo G, Cordae, Coi Leray, Babyface Ray and others as the backup and as you can see, was promoted heavily by the fest as being a big draw.

On Monday, Lil Baby let out a lengthy apology on IG ... saying his body gave out on him following his summer tour with Chris Brown, and begged the forgiveness of Vancouver, Breakout Fest and all the fans in attendance.

He should've added the cleanup crew to that list.