What Can We Learn From The Explosion Of The Latest SpaceX Prototype?

After several weeks of testing Starship prototype SN4 something went wrong minutes after a successful engine test. A massive fuel leak caused an explosion which wrecked the vehicle and cause significant damage to the test stand. As far as we know nobody was injured and there are prototypes already waiting in the wings to continue tests. THIS IS NOT RELATED TO SPACEX’s LAUCH WITH ASTRONAUTS THIS WEEKEND! I believe that unlike the first few failures due to welding quality this is not related to the manufact