You can see huge chunks of debris flying into the air on launch, and half a dozen engines were out by the time they were visible. The discolourations and asymmetry in the plume indicates damaged engines. The term of art is engine rich exhaust.
It looks like debris tore up the engines, which progressively lost more thrust and control authority as more engines failed, leading to the loss of the vehicle.
It looks like debris tore up the engines, which progressively lost more thrust and control authority as more engines failed, leading to the loss of the vehicle.