Bill Hader: Unaired Bieber 'SNL' Sketch Was 'Trainwreck'
Description:Recent 'Saturday Night Live' alum Bill Hader and two writers release an unseen sketch in which Hader starred with Justin Bieber. Hader and the two writers give commentary on what went wrong during the dress rehearsal, from jokes falling flat, to the set collapsing. Calling it the 'greatest train wreck ever,' Hader explains why it never made air. Kristina Behr has the details.(1:08)