No, there's usually no duty to help anyone, and someone who undertakes to help someone has to be good at it because they can even incur liability for helping badly so as to cause more injury.
There are certain people, like bartenders who serve alcohol to their customers, who are under a duty to them, and who can be liable for not stopping them from doing something to hurt themselves, like drinking and driving.
But generaly there's no duty to help anyone or stop them from hurting or killing themselves.
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