The dude probably has a shit load of mental problems, seeking attention via suicide is also a sign of mental issues and stress. HOWEVER, it is best to distance yourself from people like that, their problems and health is not your responsibility especially if they are venting without permission. Do not blame yourself if this person takes extreme measures. unless you are directly telling them to off themselves, physically and mentally abusing them, or treating them like dirt, it is not your fault.
Please do not interact with people like this especially if they are worsening your mental health.