Being suicidal doesn't just mean that you are planning go jump from a bridge or overdose. Being suicidal doesn't mean that you just lie in bed and check out of life, and continuously plan your death until you do it.
Being suicidal can mean that you stand a little too close to the edge of the platform. Staring at the tracks and hearing the train come closer and wishing that you would just fall or have the courage to jump.
It can mean crossing the road and not caring if you get hit by a car. Infact secretly hoping that a truck hits you and you die instantly so that your death can seem accidental and not planned.
It can mean driving a little too fast on an empty road. You don't want to cause harm to others, but you test faith by driving too fast and just maybe losing control.
It can mean wishing you had a heart attack or an illness which killed you painfully and quickly so that others wouldn't think you killed yourself.
It can mean mixing alchol and medication (or other substances together) which can cause harm or death, just so that your death will seem accidental.
Being suicidal doesn't mean that you stand with a gun to your head and scream "I don't want to live." Being suicidal can mean that you have no motivation or desire to live but you know for the sake of others you shouldn't kill yourself, so instead you wish to disappear. Or you wish for an accident, anything that would make you die but you wouldn't have to inflict it on yourself.
Being suicidal can mean that you are just surviving and waiting for your life to end.