Susan Boyle breaks down on U.S. tour

Just moments after finishing a note-perfect performance on live American television, Susan Boyle breaks down in tears.

The 48-year-old was besieged by fans as she sat in the Rock Center cafe in New York's Rockefeller Centre.

Staring straight ahead and sucking her thumb, the Scottish singer appeared withdrawn as she neared the end of a whistle-stop promotional tour of the US.

Then, visibly overcome with emotion, she bowed her head and began to sob