I think a big important clue is the legs not deploying and locking into position. The Starship lands hard and even noticeably bounces, as some of us said yesterday. If all of the legs had been locked in position, it might have withstood that better, but with only three of the six locking in place I think they all would have collapsed. In the still frames showing SN10 on the ground, it appears to be sitting with its base on the concrete pad, not on its legs.
Another big, important clue is that fire on the side of 10 as she's getting ready to land. That gets bigger, and continues even with the fire suppression system spraying water. There's evidence of a methane leak, a plumbing problem, that started when the two unneeded engines were shut down. SN10 lands trailing fire out the side. Once it was on the ground, it seems possible some amount of fire continued, eventually leading to the final conflagration.
That said, I agree with Scott that this is a validation of the entire landing sequence - from a belly flop to vertical, powered landing. (I've seen some commenter somewhere refer to this maneuver as a Crazy Elon. I'm assuming the phrase is meant to echo the Crazy Ivan maneuver. That term started in submarines as response to a Russian captain, but now is widely used.)
Meanwhile, we know that SpaceX Boca Chica has started working on clearing debris. Bluto the giant crane was moved to the landing pad area today, and there are reports that work has begun. One thing that seems to be positive here is that the pieces are much bigger and fewer than the pieces SN9 left.
Photo by Mary, @bocachicagal, of course.
Due to having morning commitments that required a night's sleep, we didn't get up for the 3:24 AM launch of Starlink-17 but the "most delayed" Falcon 9 mission went off without a hitch, successfully placing another 60 Starlink satellites in orbit and recovering Falcon 9 booster B1049 for the eighth time. We did watch the highlights in this SpaceX video this morning.
For unknown reasons, it was announced in advance that the video from the booster would not be available, so that most of what I consider the interesting things to watch weren't there to watch. There was a brief video image of the booster on the deck of the recovery drone, but the camera cut out as it was just about to land (the camera cutout happens most of the time). We don't know if this is a new policy, if something was wrong in the hardware somewhere, or exactly what was going on. I just hope they don't keep this policy.
The next Starlink launch is set for Sunday night at a more friendly time for us: 10:41 PM EST. I'm hoping the booster cameras are back for the mission.