I am assuming that these folks were using Methalamphetamines; Crystal Meth and such. That is the drug that will kill you the fastest
My oldest brother was a herion and methadone addict for many years. He declined slower than these folks but finally, 6 years ago, died of an overdose on a liverand kidneys ravaged by Hep C and other things. Purposeful or accidental, we shall never know. His son, age 38 and extrememly handsom and intelligent , is also a meth addict, now.
The drug addict is your neighbor, your brother, your children . . not some stranger.