Facebook-posting driver causes fatal crash

A woman in the US posted on her Facebook about her enjoyment of the song 'Happy' in the moments before she crashed head-on into a truck, killing her instantly.

North Carolina 32-year-old Courtney Ann Sanford updated her Facebook status at 8.33am on Thursday, one minute before she veered off a highway and through a median strip into the path of an oncoming truck.

She was believed to be referring to the Pharrell Williams song when she wrote "The happy song makes me HAPPY" in her final post before her death.

Police originally were unable to explain why Ms Sanford had crossed the median strip before her family revealed she had been on Facebook about the time of the crash.

A further investigation of her online activity showed she had also been posting selfies as she drove.

"In a matter of seconds, a life was over just so she could notify some friends that she was happy," High Point Police Lieutenant Chris Weisner told WGHB-TV.

"As sad as it is, it is a grim reminder for everyone ... you just have to pay attention while you are in the car."

The driver of the truck was uninjured.