Celebrities are sharing their tributes in remembrance of the September 11, 2001 attacks in New York City on the 22nd anniversary of the tragedy.

On Monday (Sept. 11), stars such as Khloe Kardashian, Mark Wahlberg, Leah Remini, Offset and more honored the victims and heroes of 9/11 on social media.

"It's so important to acknowledge this day not only to remember those who lost their lives but also the first responders who heroically rescued innocent people and lost their lives in the process," Remini tweeted.

"We will never forget you. To the 2,997 people we lost that day, to their families, to the heroes, the first responders, the firefighters of NYC, and to everyone impacted by this day 22 years ago. We will always remember you," Kardashian wrote in a tweet that was re-posted by her mom, Kris Jenner.

In an Instagram video, Alec Baldwin reflected on the tragedy.

"I wanted to take a moment to mention that I watched the 60 Minutes piece about 9/11 that was on tonight, Sunday night. It was really, really tough. It was a painful re-visitation of the whole situation. As I've mentioned in some posts previously, on the day of 9/11, I was on Long Island, rehearsing to do a play," Baldwin shared.

READ MORE: Celebrities With Unbelievable September 11 Stories

"22 years later, hard to believe it's been 22 years. I remember that like it was yesterday," he added.

Actress Octavia Spencer echoed Baldwin's statement in her own Instagram post, writing, "22 years later and it still feels like I was just watching the tragedy unfold live on television."

"We all may see things differently, we may not always agree but I know on this day without a shadow of doubt, we all came together as one, we were unified, the courage, outpouring of humanity and fierce solidarity reminded us what we stand for," country singer Jessie James Decker shared.

See more celebrities' 9/11 tributes, below:

See 20 Ways America Has Changed Since 9/11

For those of us who lived through 9/11, the day’s events will forever be emblazoned on our consciousnesses, a terrible tragedy we can’t, and won’t, forget. Now, two decades on, Stacker reflects back on the events of 9/11 and many of the ways the world has changed since then. Using information from news reports, government sources, and research centers, this is a list of 20 aspects of American life that were forever altered by the events of that day. From language to air travel to our handling of immigration and foreign policy, read on to see just how much life in the United States was affected by 9/11.