Adam Lambert’s top notch performance wasn’t the big American Idol headline of the night. Part of the set reportedly collapsed this afternoon (May 5).

One of the towers broke, and, just before dress rehearsal started, glass and other debris began to fall. “We’ve had an unconventional day here,” Ryan Seacrest said on air.

According to TMZ, the problem stemmed from the staircase that Ryan walks down at the beginning of the show. It’s supposed to retract as he walks, but it retracted too soon, hurting stage manager Debbie Williams. She suffered a “nasty gash” on her leg and was taken to the hospital.

Meanwhile, look for Paula Abdul to hit the stage tomorrow night (well, not literally) when she performs her new single (I’m Just) Here For the Music.

No Doubt is slated to appear as well.