The Japanese newspace company Interstellar Tech released two uncut
high speed videos of their liquid sounding rocket crashing back on its
launch mount. An unusual level of transparency.
https://phys.org/news/2018-08-high-speed-cameras-momo-failure-unprecedented.html
A few really spectacular scenes in there. Flames were going in bad
directions very early. Hot gas seals suck, and should be avoided.