Please help

A friend of mine (we met when he came to europe for an exchange 5 years ago) and I remained "pen pals" over whatsapp (he lives in florida) until recently... obviously with time we texted less, but we still kept in touch. Now his dad got diagnosed with a tumor and my friend was feeling down and wanted space so I gave him space. He texted me 2 weeks later " I fucking suck, I seduced a married woman. I suck"

Since then, April 13, he hasn't been online. Has not answered my texts or calls.

How do I know if he's still alive?!? I only have his contact I really don't know what to do. He is/was(?) Very suicidal and was not in therapy bc he couldn't afford it. I just want to know if there's a way to know if someone's alive from overseas.