While the literature in the area is incomplete, there is no definitive link between SES and suicide. This does not preclude localised tendencies nor trends in a population during a certain period of time. Nobody is suicidal at all times. The risk of suicide for any individual varies across time, as circumstances change. This is why it is important for regular assessments of the level of risk in individuals who are 'at risk'.
Every death is preventable.
No matter how well intentioned, alert and diligent people's efforts may be, there is no way of preventing all suicides from occurring. The problem is that we lack a complete understanding of youth suicide and know more about what is not known than what is fact.