Widget containers or widgets randomly disappeared on my website!

Hello WordPress Community,

I need your help. I’m the web editor of a student publication at my college (www.hillsdalecollegian.com) and when I got back from spring break, I noticed that a number of widget containers and in other instances the widgets, but not the containers, disappeared from my website **seemingly randomly.** I rely heavily on widgets and plugins, so this is a big problem.
My website is built on the Thesis theme (2.2.3) if that helps.
I’m beside myself because to my knowledge, no one has touched the website since I left campus for spring break. I replaced the missing widgets as best I could, but my knowledge of html and css is limited and was only able to restore so much. Additionally, after making the patches to the website, I saved my current Thesis skin.

Do you know why widgets might have disappeared? Additionally, how can I stop this from happening again in the future?