I'm Leaning Toward a Simple Explanation

I think everything that went wrong with Starship's first Flight Test can be traced to the OLM and especially the concrete underneath it disintegrating in the eight to ten seconds that the first stage built up enough thrust to lift off.  Flying debris took out engines, and damaged the Hydraulic Power Units (HPUs) that power the engines to gimbal.  A system that's going away on the next generation Raptor engines, to be replaced with some batteries they got from a Tesla.  

Earlier today, I added to the comments on yesterday's post a link to a photograph that showed up today in the NASASpaceflight.com thread devoted to the mission.  Later on, I edited the post to include the photograph and edited the comment to tell the story.  This link will take you directly to the photograph.  It shows the damage to the OLM was far worse than we saw yesterday.

It's also worth watching Scott Manley, as usual, who has some good observations and points out things to notice.  At just over 10 minutes, there's a lot of information in it.  This picture is a freeze-frame from T+07 seconds, and I've circled what appears to be a flying L-shaped chunk of concrete.  There are at least two other enormous pieces of debris flying up around the same time in the video (14 to 17 seconds from the start), both to the left and right of this one. Starship is 9 meters diameter (nearly 30feet); that makes the concrete chunk look at least 20 feet long and 5 ft vertically.

Screen capture from Scott's video, processed to enhance contrast and visibility of that chunk by me.

There have been reports of the hydraulic power units (HPUs) failing early, possibly due to chunks like this.  There are reports of damage all around the launch complex.  This video shows a NASA Spaceflight van getting pounded by debris, and smashed up badly, along with a lot of other things being damaged. Cameras, perhaps telescopes, lots of thing get knocked over.

In the early days of building up the "stage zero" launch infrastructure there was talk about building a flame trench or a water deluge system like we typically see at the major launch facilities (KSC, Vandenberg SFB, and so on).  There was a quote going around that Musk had said he had hoped it wouldn't be needed because a water deluge wasn't doable on Mars and I think the trench didn't seem likely, either.  I think the reasons are more mundane.  Starbase Boca Chica is in the middle of miles of federally-controlled wetlands.  The water table is very close to the surface, and any water collected probably would need to be purified in some way, approved by the EPA or both. 

I may be totally off base here, but it seems to me that at Boca Chica they have the boosters and ships for the next few missions queued up.  They will need testing and won't be able to get tested.  The Starship pad and facilities at the Kennedy Space Center are a lot closer to being able to support new tests than Boca Chica, and will be for months.   Another deluge system to add to the wetlands on Cape Canaveral doesn't sound anywhere near as threatening, specifically because it will be "another" water deluge or flame trench, rather than the only one within 500 miles.  They should move those next couple of Starships over here for testing, even to launch the next Starship.