Many celebs, like Rob Lowe, took to Twitter today to remember 9/11.

Here are many that we found:

I'll never forget. I was there. #NeverForget #september11 #911Memorial @Sept11Memorial

A photo posted by JW Cortés (@jwcortes) on

My view…Long live NY

A photo posted by Richard Marx (@therichardmarx) on

Also, actor Denis Leary remembered “three good men who died that dreadful day.”