[fatboy]

That's a bit I find surprising. I would have thought that working out if the pad was up to the job would be one of the easier rocket-science tasks they were faced with.

[sinuhe69]

Was well not the most critical part, though.

[simonh]

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.

[a3n]

I'm guessing that undiverted flame and related debris could ricochet up to the rocket and cause problems.

[infogulch]

Which could have been the cause of the dead engines during flight, which could have been the reason why it didn't make altitude and didn't separate.