Family history of suicide

I am looking for some advice as to how much to tell my children about suicide in our family. My son is 3 and my daughter is 6 months, so I have time to figure out what to say, but I'm so scared that telling them will plant the seed of suicide as an option... My mother, sister, aunt, uncle, grandma, and grandpa all committed suicide over the last 30 years and I feel like it was kind of like a domino effect. My grandma on my dads side was first (30 years ago) and it affected my aunt and uncle to such a degree that they ended up taking their own lives soon after. 11 years ago my mother committed suicide, which then led to my grandpa (her father) and then my sister committing suicide in the last year. My sister struggled for 10 years with suicidal thoughts and quite often would make bad decisions with drugs and stealing with the backup plan of killing herself if things got too bad (which they eventually did). I was quite young when my dad told me about the deaths in his family and I think that led to me making a suicide attempt at age 10 because, in my mind, I was unhappy so that was the best way to deal with those feelings. I don't want my children growing up with that mentality and I wonder if it's justifiable to not tell them that 6 family members chose to end their lives. I hate the idea of lying or hiding things from my children but could the omission save their lives? Or would the secret be too hard to keep and end up doing more damage on the long run? Sorry for the long post but I think the background info is important... Any advice would be appreciated!