It's the "Grandparent SCAM." Also known as the family emergency scam. Block the number. Here's some information:
Grandparent Scam
https://www.consumer.ftc.gov/articles/0204-family-emergency-scams
http://www.consumerfed.org/pdfs/Grandparent-Scam-Tips.pdf
http://opinionator.blogs.nytimes.com/2015/04/09/the-grandparent-scam/?_r=0