It’s hard to believe that only 10 years ago, our nation was in mourning for the thousands of lives lost on 9/11/01.

For the 10 year anniversary, several AMP Radio celebrities sought to express their grief via social media.

Check out what they all had to say on Twitter.

Today marks 10 years since 1 of the most devastating events the world has ever seen!Lets remember those we lost and pray for their loved 1's—
Rihanna (@rihanna) September 12, 2011

Sick in bed and watching the memorials today. Taking time to remember all the lost & all the heroes. #GodBlessAmerica—
Katy Perry (@katyperry) September 11, 2011

http://twitter.com/#!/S_C_/status/112866311830380544