I went back and checked, and actually not much pops out about my transits and secondary progressions when my mother died. (Although there's kind of a long story.) Progressed moon in Sagittarius partile trine my natal Leo moon, and counter-parallel my natal moon within a degree. Solar arc Mars in Aries partile trine my natal moon. I also looked at tertiary progressions but wasn't getting any hits.
The long story is that my mother (a sun-Scorpio who died in 1984) went through a really difficult time towards the end of her life: depression and alcoholism. I think that if she thought that suicide was morally justified, she would have committed suicide in one go. As it was, she became a recluse, and I think she effectively killed her self by drinking to the point of passing out, with a few hematomas as evidence of falling and hitting her head. My siblings and I naturally felt dreadful about this, but she didn't want anyone monitoring her and rebuffed our offers of support and help. None of us was living near her at the time, and we were all working.
I read once somewhere that an unhappy Scorpio goes through 3 stages:
1. Lashing out with her stinger at others,
2. Stinging herself,
3. Dying from her own poison.
Yes, I think so.
My mother died with transiting Pluto partile conjunct her natal sun. However, she had been living a very difficult Bad Pluto kind of life for about 6 years before she died, and I think of her generation as opposed to psychotherapy on the grounds that it was just for "crazy people," so she rebuffed any help. She was treated for depression with medication. Transiting Pluto at the time was inexorably activating her natal T-square, and I think it all became too much for someone who was already terribly fragile.
My mother died alone in her apartment, discovered by my cousin in town, who had a key to my mother's apartment. No autopsy was done. Back then, age 71 was apparently considered death of old age.
I flew back home to clean out my mother's apartment, including the feces she had smeared on the bathroom walls.
Very Scorpio-Plutonian, and I do think of her death more as a lengthy suicide, which complicates the "death star" matter. Was my mother's death a welcome release for her? For me??
Needless to say, however, a lot of people survive transiting Pluto conjunct their suns.