This is exactly why I don't plan on visiting the SkyDeck at Willis Tower. That and a fear of heights, but mainly the idea that the glass could crack and break right underneath me.

That's exactly what happened to visitors on Monday.

Way up on the 103rd floor of the Willis Tower observation deck people were treated to an extra scare when the protective layer on the SkyDeck cracked.

Thankfully the protective layer did its job and no one was in real danger, but could you imagine standing there when it started to crack? YIKES!!!

One Chicago-area resident, Jesus Pintado, caught the terrifing moment on video:

This isn't the first time this has happened either.

Back in 2014, the protective layer did the same thing.

In both instances, no one was in danger or hurt.