Keith Urban 's sudden onstage collapse in Tennessee during the final show of his grueling six-month tour was a playful joke – but friends fear the 58-year-old hitmaker is in real danger of a mental meltdown amid his divorce from Nicole Kidman , RadarOnline.com can reveal.

The Somebody Like You singer staggered backward and fell down at Nashville 's Bridgestone Arena on October 17 after a fan teasingly told him her name was Nicole. Article continues below advertisement

Keith Is 'Running On Empty' Following The Split Tap Here To Add Radar Online as A Trusted Source Article continues below advertisement Article continues below advertisement

However, sources told RadarOnline.com the incident has sparked worries for Urban as his 19-year marriage ends and he weather

See Full Page