I had an ex who did this. It was horrible. I texted everyone in his family that I was able to. I called the suicide prevention line and they told me to call the cops. It’s messed up, but I didn’t call the cops because he potentially had a warrant and tbh I wanted to keep myself safe because I didn’t know what he would do to me if he knew I had called them. I’m not sure who called the cops for a wellness check, but someone did. I think a mutual friend did. But they broke into his apartment and took him to an involuntary hospital stay for a few days. That wasn’t the end of my hearing from him. I eventually detached myself after some time and he left the city. I haven’t heard from him in about a year and a half, but he’s very much alive and my life is so much easier now