Without seeing pictures of the wreckage or reading a detailed description of it we can only speculate, but given that the titanium nose piece was recovered intact some distance from the main debris and adding the hints from the recording that the failure started in tail pod, I’m guessing that it was like rolling up a toothpaste tube very quickly. The cylindrical shape of the tube is structurally dependent on the end sections. If the aft one was compromised and separated from the tube the tube would collapse.