Funny, in the history of the Concentration Camp holocaust I have read, never before heard of such pre-gas chamber suicides. My understanding that most never knew they were heading to certain death although those slave Jews who worked the handling surely did. Maybe those are to whom you refer.
In the cases of the Holocaust or the 911 tower jumpers, I reason that knowing certain death and choosing some action that is technically suicide is not the same as our dear Mr. Williams, in any slightest degree.