Tiga tahun yang lalu, orang tua itu ditinggal mati anak laki-laki semata wayangnya.

English Translation

The old man had his only son die three years ago.

Tip: “wayang” is a type of Indonesian traditional shadow puppet performance.
But according to KBBI “semata wayang” is a set phrase, meaning “the only” (= hanya satu-satunya),