Today’s Pic of the Day features a serene New York City skyline on September 10, 2001, where the iconic Twin Towers of the World Trade Center stood tall and unchanged as they reached into the clouds.

Captured from the Staten Island Ferry, this photograph, taken just a day before the tragic events of the 9/11 attacks—one of the darkest days in American history—evokes a sense of calm and normalcy that few could imagine would soon be shattered.

Who could have imagined that the beautiful weather that week was just the calm before the storm leading up to that tragic Tuesday morning?

Not only did the events of that day change the world instantly, but they would also ripple through the following two decades and beyond.

Looking at images like this, I often wonder about the people who worked in the Twin Towers but happened to be on vacation that day or week—those who were scheduled to return later, maybe even on Wednesday, September 12. Can you imagine the overwhelming mix of relief and grief they must have felt?

And then, of course, there’s the survivor’s guilt of those who made it out, especially those who were able to escape the collapse.

It’s staggering to think how, in just a single day, the norm was shattered, and the lives of hundreds of thousands were forever altered.

Monday’s Headlines You Never Knew: What Was Happening on September 10

As we look at this peaceful image of the Twin Towers on September 10, 2001, it’s a reminder that life was just moving along like any other day.