Looking at the Wikipedia article you linked, I don't see any definitive, authoritative sources of information that directly links KiwiFarms and these horrible events other than random tweets posted by people on the internet.
After looking through 5-6 different sources cited in the bottom of the article, I don't even see any references or screenshots of the actual website used in reporting, just journalists taking what other people are saying as fact.
The site owner posted this rebuttal to assignment of blame for these suicides, which I find compelling. For instance, the widow of one victim decried Vice News (one source referenced in the article) for using her death to attack Kiwi Farms: