Mike, the account given here by a man named Tom Rudolph (https://www.vhpa.org/KIA/incident/68020818KIA.HTM) indicates that 66-01128 was chalk 5 of 6 and was hit with heavy ground fire after takeoff. 66-15125 was reportedly hit by an RPG after take off. Much respect for our flying brothers, present and departed. So sad.
Hadn't seen that report. The flight came under heavy fire on exit, 128 gave a belch of white out the hell hole (hole in the fuselage bottom where the cargo hook hangs from, transmission right over it) and both blades snapped off, turned turtle and nose down (a Huey's no blade drop position). I think the white fog was transmission fluid from the transmission case rupturing when the transmission seized, which would also account for the blades snapping off. Under the circumstances, the guess was something hit the transmission and did enough damage to the gears it jammed. The aircraft just shattered when it hit, pieces were put in a cargo net, lot of it wasn't recovered. First company fatality, whole crew, really a shock when we'd done over 3 months of flying without even a serious wound, although we'd already lost some helicopters. That week after Tet, things were still hot, and the adventure kids turned into serious men that week, and pretty much stayed that way.
Almost forgot, rpg's were something we did fear. A gunship caught two of them in one pass, rolled over on it's side and the crewchief kicked the side door shut just in time so it slid across a rice paddy to a stop without hurting anyone. I've got a photo of it somewhere. Huey's seldom survived an rpg hit, at least none of ours did.