Twenty-four years ago Thursday, evil took 2,977 innocent lives in the deadliest terror attack ever carried out on American soil.

Among those murdered were my brother Gary, my best friend Doug, and 656 other colleagues and friends of mine from Cantor Fitzgerald.

I’m only alive today because that fateful Tuesday was my oldest son’s first day of kindergarten.

That morning, instead of going to our offices in the 101st through 105th floors of the North Tower of the World Trade Center, I joined my wife in taking our son to school.

At some point, my phone started ringing but disconnected each time I’d answer.

I only later learned that it was my brother Gary trying to call from the building to say goodbye.

Once I heard that a plane had struck the World Trade Center, I raced downtown.

I arrived at the base of the building and started grabbing people as they came out the doors, hoping that some of my people were able to escape. None did.  

If you think about all the people you work with, I guarantee you don’t appreciate how important they actually are to you.

We all underestimate how central our colleagues are in our lives. Most people spend more time with their co-workers than they do with their families.

People don’t often articulate the love they feel for their colleagues, or even think it’s accurate to call it love. But it is.

When they’re ripped from you in an instant, your heart collapses.

Losing my colleagues — my partners, my friends — showed me the depths of that love.

I cried every single day until Oct. 21, 2004.

When I went to bed that night, I remember telling my wife it was the first day I hadn’t cried.

The grief never completely leaves.

There’s too much to process. Too much death and pain to fully comprehend at once.

So much so that when someone would mention the name of a co-worker who died that day, it was like they were killed then and there.

That pain would flood back all over again because I hadn’t fully processed each of the hundreds of deaths.

Even now, I still get emotional when I speak about 9/11 because it is a wound that never fully heals.

Today, after rebuilding Cantor Fitzgerald from the ground up, I serve as our nation’s 41st secretary of Commerce.

It’s been eight months, and in that time I have seen America at its core.

What you learn in this job is how profoundly beautiful and extraordinary this country is, but also how desperately our adversaries wish us harm.

Make no mistake: If given the chance, the monsters who orchestrated the Sept. 11 attacks, and those like them, would do it again.

And again. And again.

That’s exactly why we cannot be complacent.

The greatness of America lies in how we live, think and act — a bold contrast to our adversaries.

There’s no part of us as Americans that operates in the same realm as those terrorists. We’re compassionate, generous, and honorable.

Through my service to the country, I have fallen ever more deeply in love with America.

I’ve seen the tremendous way our military, our government, our first responders and our people confront challenges and threats.

I’ve seen the courage and clarity with which we defend our values.

And most importantly, I’ve seen how the evil of those who wish to destroy us stands out in stark contrast to the goodness that defines our country.

Twenty-four years after that dark day, I thank God that we have a president in the Oval Office who understands this reality, and who unapologetically has the backs of the American people.

He’s committed to aggressively rooting out evil wherever it rears its head so it can never again inflict the devastation and incomparable pain of 9/11.

On Wednesday, as a deranged gunman murdered my great friend Charlie Kirk for his political views, we were reminded that the battle against evil is never over.

But just as we did after 9/11, we will endure, we will fight on, and we will never, ever surrender.

Charlie will be remembered for his kindness, his loyalty and his devotion to America.

I’m confident his killer will face swift justice, because evil has no place in this country.

Fiercely defending America and our people from threats, both internal and external, doesn’t mean we’ve given up our compassion and moral high ground as a country.

We doggedly fight evil while still operating righteously.

That duality is what makes America extraordinary.

On Sept. 11, 2001, I lost nearly everything.

But I gained unshakeable faith in a nation that rebuilds, endures — and never surrenders to evil.

Howard Lutnick serves as secretary of Commerce.