Yep, the incident back in 21" was a pin failure. It sheared and a main rotor blade departed. The guys and gals that crew the fire fighting helos I mentioned earlier have a tough and very dangerous job.
If you look closely at the still images from the video(s), you will see that the main rotor is detached and is one of the several objects descending along with the tail boom.
I can’t even imagine the terror the occupants were experiencing as the fuselage was falling towards the river. Hope I die in my sleep.