I know of 2 successful attempts.
One D,fed Man hung himself .End of story.Poor Guy.
The second was one of the worse stories i heard from the Religion.
A Brother finds out his new Wife is cheating on Him and is so distraught he Gasses himself in his Car.The Evil Bitch turns up at his Funeral in the same car,with her new Boyfriend.
Actually,that is the worse story i ever heard from the Religion.I dont think you can blame JW,s for that ,but it is related.It happened about 15 Years ago in a relatively nearby Cong,and affected lots of People ,including me a young Pioneer at the time.He was roughly the same Age as me.The Wife was D,fed.Big fucking deal.That poor Lad.
Ive known of quite a few Suicide attempts.