Driving and saw smoke at signal. Pulled over smelled fuel, opened hood and found the the metal line on injector #5 (from the front end) from the rail to the injector was spraying fuel. The leak is on the metal tube right after it comes out of the bolt at the injector. Also noticed the clamp that holds the line was loose, would that cause the failure? Is the a common failure?

 

Also noticed the clamp that holds the line was loose, would that cause the failure? Is the a common failure?

Yes and Yes.
Replace the injector line and check/tight all the other clamps and holding brackets for all the injector lines.