From what I gather they lost telemetry at the re ignition phase after flipping over and it may have auto destructed at altitude. Interesting views of flashes and flames on one engine and lots of what looked like propellant flowing past rocket, I think it buckled during the gliding flip over phase. Exploded say around 400 meters or so off ground by the debris field and time to ground impacts.
Believe only one engine lighted properly, a possible turbo pump failure occurred, and also possibly an automated system initiated a vehicle destruct based on trajectory error.