The EXACT same thing happened to me. Guy called, claiming my relative was in a horrible car accident and threatens a ransom of 2000 dollars or else he will kill them. I come to find out shortly after the relative is safe and sound relaxing in car on lunch break at work eating Subway. The police are on his tail.
Some guy calls me telling me that someone I know was involved in a car accident and ran over a 6 yr old. He tells me that they have taken this person and if I wanted to see him alive again that I was to western Union $2000 to their account. If I did not comply he would put a bullet in my friend's head. I was on my way to a western Union when it dawned on me that he would not give me any details about my friend's appearance or let me talk to him. I called his bluff and told him I wasn't gonna send him anything and hung up. My sister suggested I Google the number and found this site. I haven't heard from my friend, but I am relieved that I made the right decision.