I may be wrong but I think such errant rocket explosions have happened before with Hamas or other Islam terrorist groups.
Video of explosion at Gaza City hospital, where hundreds have reportedly died
https://rumble.com/v3pxtms-video-of-explosion-at-gaza-city-hospital-where-hundreds-have-reportedly-die.html
Under power - sounds a lot like an air-to-ground missile, the same as, or similar to, what IDF have been using to hit targets in the Gaza Strip. Different sound than a rocket under power - considering whatever is the age of my hearing.