Something similar happened to a nanny that worked for me.
Her phone rang and a male voice said something like, "We have your son and going to kill him unless you send $50,000 right now.
In the background she could hear a male voice screaming. The caller said we're beating your son and won't stop beating him until we get the money.
The nanny said, I don't have any money, but I can sell my house. The caller agreed.
~
Finally, I got involved. Told her to call her son right now. She called her son's cell phone and he answered and said everything is fine; I don't know what you're talking about.
It was a scam!