Do Say Don't Say Reason
A person ATTEMPTED SUICIDE, DIED BY SUICIDE, or KILLED THEMSELVES. A person COMMITTED SUICIDE. Commit connotes a legal implication and harkens back to the days when suicide was illegal.
They are a SUICIDE ATTEMPT SURVIVOR. They had a FAILED suicide attempt They also have LIVED EXPERIENCE.
A person COMPLETED SUICIDE when they die by suicide. It was a successful SUCCESSFUL SUICIDE. There's nothing positive about a person ending their life prematurely.
A person who has someone they care about die by suicide is a SUICIDE LOSS SURVIVOR. Loss survivors describe this loss as a most complicated grief.