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When was J. Paul Getty's grandson kidnapped?
In Rome on July 10, 1973, 'Ndrangheta kidnappers abducted J. Paul Getty's 16-year-old grandson, John Paul Getty III, and demanded a $17 million payment for his safe return.
What did the kidnappers of J. Paul Getty's grandson, John Paul Getty III, want from J. Paul Getty?
In Rome on July 10, 1973, 'Ndrangheta kidnappers abducted J. Paul Getty's 16-year-old grandson, John Paul Getty III, and demanded a $17 million payment for his safe return.
Why was J. Paul Getty's grandson, John Paul Getty III, the target?
When Italian gangsters abducted the grandson of J. Paul Getty, the richest man in the world, they thought they’d seized an easy fortune.

Question: how old was his grandson?
Self-contained rewrite: How old was J. Paul Getty's grandson, John Paul Getty III, when he got kidnapped?